From: "Mike Pagano" <mpagano@gentoo.org>
To: gentoo-commits@lists.gentoo.org
Subject: [gentoo-commits] proj/linux-patches:5.12 commit in: /
Date: Tue, 27 Apr 2021 11:53:13 +0000 (UTC) [thread overview]
Message-ID: <1619524352.0e42ec88e771cb237508891316a7db9d70cf0ea5.mpagano@gentoo> (raw)
commit: 0e42ec88e771cb237508891316a7db9d70cf0ea5
Author: Mike Pagano <mpagano <AT> gentoo <DOT> org>
AuthorDate: Tue Apr 27 11:52:32 2021 +0000
Commit: Mike Pagano <mpagano <AT> gentoo <DOT> org>
CommitDate: Tue Apr 27 11:52:32 2021 +0000
URL: https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=0e42ec88
Add BMQ Patch 5.12-r0, default ALT SCHED=n
Signed-off-by: Mike Pagano <mpagano <AT> gentoo.org>
0000_README | 8 +
5020_BMQ-and-PDS-io-scheduler-v5.12-r0.patch | 9805 +++++++++++++++++++++++
5021_BMQ-and-PDS-gentoo-defaults-v5.12-r0.patch | 13 +
3 files changed, 9826 insertions(+)
diff --git a/0000_README b/0000_README
index e856f62..bbb058a 100644
--- a/0000_README
+++ b/0000_README
@@ -66,3 +66,11 @@ Desc: Add Gentoo Linux support config settings and defaults.
Patch: 5013_enable-cpu-optimizations-for-gcc10.patch
From: https://github.com/graysky2/kernel_gcc_patch/
Desc: Kernel patch enables gcc = v10.1+ optimizations for additional CPUs.
+
+Patch: 5020_BMQ-and-PDS-io-scheduler-v5.12-r0.patch
+From: https://gitlab.com/alfredchen/linux-prjc
+Desc: BMQ(BitMap Queue) Scheduler. A new CPU scheduler developed from PDS(incld). Inspired by the scheduler in zircon.
+
+Patch: 5021_BMQ-and-PDS-gentoo-defaults-v5.12-r0.patch
+From: https://gitweb.gentoo.org/proj/linux-patches.git/
+Desc: Set defaults for BMQ. Add archs as people test, default to N
diff --git a/5020_BMQ-and-PDS-io-scheduler-v5.12-r0.patch b/5020_BMQ-and-PDS-io-scheduler-v5.12-r0.patch
new file mode 100644
index 0000000..81f4c55
--- /dev/null
+++ b/5020_BMQ-and-PDS-io-scheduler-v5.12-r0.patch
@@ -0,0 +1,9805 @@
+diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
+index 04545725f187..d560166b0cf1 100644
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -4725,6 +4725,12 @@
+
+ sbni= [NET] Granch SBNI12 leased line adapter
+
++ sched_timeslice=
++ [KNL] Time slice in us for BMQ/PDS scheduler.
++ Format: <int> (must be >= 1000)
++ Default: 4000
++ See Documentation/scheduler/sched-BMQ.txt
++
+ sched_debug [KNL] Enables verbose scheduler debug messages.
+
+ schedstats= [KNL,X86] Enable or disable scheduled statistics.
+diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
+index 1d56a6b73a4e..e08ffb857277 100644
+--- a/Documentation/admin-guide/sysctl/kernel.rst
++++ b/Documentation/admin-guide/sysctl/kernel.rst
+@@ -1515,3 +1515,13 @@ is 10 seconds.
+
+ The softlockup threshold is (``2 * watchdog_thresh``). Setting this
+ tunable to zero will disable lockup detection altogether.
++
++yield_type:
++===========
++
++BMQ/PDS CPU scheduler only. This determines what type of yield calls
++to sched_yield will perform.
++
++ 0 - No yield.
++ 1 - Deboost and requeue task. (default)
++ 2 - Set run queue skip task.
+diff --git a/Documentation/scheduler/sched-BMQ.txt b/Documentation/scheduler/sched-BMQ.txt
+new file mode 100644
+index 000000000000..05c84eec0f31
+--- /dev/null
++++ b/Documentation/scheduler/sched-BMQ.txt
+@@ -0,0 +1,110 @@
++ BitMap queue CPU Scheduler
++ --------------------------
++
++CONTENT
++========
++
++ Background
++ Design
++ Overview
++ Task policy
++ Priority management
++ BitMap Queue
++ CPU Assignment and Migration
++
++
++Background
++==========
++
++BitMap Queue CPU scheduler, referred to as BMQ from here on, is an evolution
++of previous Priority and Deadline based Skiplist multiple queue scheduler(PDS),
++and inspired by Zircon scheduler. The goal of it is to keep the scheduler code
++simple, while efficiency and scalable for interactive tasks, such as desktop,
++movie playback and gaming etc.
++
++Design
++======
++
++Overview
++--------
++
++BMQ use per CPU run queue design, each CPU(logical) has it's own run queue,
++each CPU is responsible for scheduling the tasks that are putting into it's
++run queue.
++
++The run queue is a set of priority queues. Note that these queues are fifo
++queue for non-rt tasks or priority queue for rt tasks in data structure. See
++BitMap Queue below for details. BMQ is optimized for non-rt tasks in the fact
++that most applications are non-rt tasks. No matter the queue is fifo or
++priority, In each queue is an ordered list of runnable tasks awaiting execution
++and the data structures are the same. When it is time for a new task to run,
++the scheduler simply looks the lowest numbered queueue that contains a task,
++and runs the first task from the head of that queue. And per CPU idle task is
++also in the run queue, so the scheduler can always find a task to run on from
++its run queue.
++
++Each task will assigned the same timeslice(default 4ms) when it is picked to
++start running. Task will be reinserted at the end of the appropriate priority
++queue when it uses its whole timeslice. When the scheduler selects a new task
++from the priority queue it sets the CPU's preemption timer for the remainder of
++the previous timeslice. When that timer fires the scheduler will stop execution
++on that task, select another task and start over again.
++
++If a task blocks waiting for a shared resource then it's taken out of its
++priority queue and is placed in a wait queue for the shared resource. When it
++is unblocked it will be reinserted in the appropriate priority queue of an
++eligible CPU.
++
++Task policy
++-----------
++
++BMQ supports DEADLINE, FIFO, RR, NORMAL, BATCH and IDLE task policy like the
++mainline CFS scheduler. But BMQ is heavy optimized for non-rt task, that's
++NORMAL/BATCH/IDLE policy tasks. Below is the implementation detail of each
++policy.
++
++DEADLINE
++ It is squashed as priority 0 FIFO task.
++
++FIFO/RR
++ All RT tasks share one single priority queue in BMQ run queue designed. The
++complexity of insert operation is O(n). BMQ is not designed for system runs
++with major rt policy tasks.
++
++NORMAL/BATCH/IDLE
++ BATCH and IDLE tasks are treated as the same policy. They compete CPU with
++NORMAL policy tasks, but they just don't boost. To control the priority of
++NORMAL/BATCH/IDLE tasks, simply use nice level.
++
++ISO
++ ISO policy is not supported in BMQ. Please use nice level -20 NORMAL policy
++task instead.
++
++Priority management
++-------------------
++
++RT tasks have priority from 0-99. For non-rt tasks, there are three different
++factors used to determine the effective priority of a task. The effective
++priority being what is used to determine which queue it will be in.
++
++The first factor is simply the task’s static priority. Which is assigned from
++task's nice level, within [-20, 19] in userland's point of view and [0, 39]
++internally.
++
++The second factor is the priority boost. This is a value bounded between
++[-MAX_PRIORITY_ADJ, MAX_PRIORITY_ADJ] used to offset the base priority, it is
++modified by the following cases:
++
++*When a thread has used up its entire timeslice, always deboost its boost by
++increasing by one.
++*When a thread gives up cpu control(voluntary or non-voluntary) to reschedule,
++and its switch-in time(time after last switch and run) below the thredhold
++based on its priority boost, will boost its boost by decreasing by one buti is
++capped at 0 (won’t go negative).
++
++The intent in this system is to ensure that interactive threads are serviced
++quickly. These are usually the threads that interact directly with the user
++and cause user-perceivable latency. These threads usually do little work and
++spend most of their time blocked awaiting another user event. So they get the
++priority boost from unblocking while background threads that do most of the
++processing receive the priority penalty for using their entire timeslice.
+diff --git a/fs/proc/base.c b/fs/proc/base.c
+index 3851bfcdba56..732636ac3fd3 100644
+--- a/fs/proc/base.c
++++ b/fs/proc/base.c
+@@ -476,7 +476,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
+ seq_puts(m, "0 0 0\n");
+ else
+ seq_printf(m, "%llu %llu %lu\n",
+- (unsigned long long)task->se.sum_exec_runtime,
++ (unsigned long long)tsk_seruntime(task),
+ (unsigned long long)task->sched_info.run_delay,
+ task->sched_info.pcount);
+
+diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h
+index 8874f681b056..59eb72bf7d5f 100644
+--- a/include/asm-generic/resource.h
++++ b/include/asm-generic/resource.h
+@@ -23,7 +23,7 @@
+ [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \
+ [RLIMIT_SIGPENDING] = { 0, 0 }, \
+ [RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \
+- [RLIMIT_NICE] = { 0, 0 }, \
++ [RLIMIT_NICE] = { 30, 30 }, \
+ [RLIMIT_RTPRIO] = { 0, 0 }, \
+ [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \
+ }
+diff --git a/include/linux/sched.h b/include/linux/sched.h
+index ef00bb22164c..2290806d8af2 100644
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -35,6 +35,7 @@
+ #include <linux/rseq.h>
+ #include <linux/seqlock.h>
+ #include <linux/kcsan.h>
++#include <linux/skip_list.h>
+ #include <asm/kmap_size.h>
+
+ /* task_struct member predeclarations (sorted alphabetically): */
+@@ -670,12 +671,18 @@ struct task_struct {
+ unsigned int ptrace;
+
+ #ifdef CONFIG_SMP
+- int on_cpu;
+ struct __call_single_node wake_entry;
++#endif
++#if defined(CONFIG_SMP) || defined(CONFIG_SCHED_ALT)
++ int on_cpu;
++#endif
++
++#ifdef CONFIG_SMP
+ #ifdef CONFIG_THREAD_INFO_IN_TASK
+ /* Current CPU: */
+ unsigned int cpu;
+ #endif
++#ifndef CONFIG_SCHED_ALT
+ unsigned int wakee_flips;
+ unsigned long wakee_flip_decay_ts;
+ struct task_struct *last_wakee;
+@@ -689,6 +696,7 @@ struct task_struct {
+ */
+ int recent_used_cpu;
+ int wake_cpu;
++#endif /* !CONFIG_SCHED_ALT */
+ #endif
+ int on_rq;
+
+@@ -697,13 +705,33 @@ struct task_struct {
+ int normal_prio;
+ unsigned int rt_priority;
+
++#ifdef CONFIG_SCHED_ALT
++ u64 last_ran;
++ s64 time_slice;
++#ifdef CONFIG_SCHED_BMQ
++ int boost_prio;
++ int bmq_idx;
++ struct list_head bmq_node;
++#endif /* CONFIG_SCHED_BMQ */
++#ifdef CONFIG_SCHED_PDS
++ u64 deadline;
++ u64 priodl;
++ /* skip list level */
++ int sl_level;
++ /* skip list node */
++ struct skiplist_node sl_node;
++#endif /* CONFIG_SCHED_PDS */
++ /* sched_clock time spent running */
++ u64 sched_time;
++#else /* !CONFIG_SCHED_ALT */
+ const struct sched_class *sched_class;
+ struct sched_entity se;
+ struct sched_rt_entity rt;
++ struct sched_dl_entity dl;
++#endif
+ #ifdef CONFIG_CGROUP_SCHED
+ struct task_group *sched_task_group;
+ #endif
+- struct sched_dl_entity dl;
+
+ #ifdef CONFIG_UCLAMP_TASK
+ /*
+@@ -1388,6 +1416,15 @@ struct task_struct {
+ */
+ };
+
++#ifdef CONFIG_SCHED_ALT
++#define tsk_seruntime(t) ((t)->sched_time)
++/* replace the uncertian rt_timeout with 0UL */
++#define tsk_rttimeout(t) (0UL)
++#else /* CFS */
++#define tsk_seruntime(t) ((t)->se.sum_exec_runtime)
++#define tsk_rttimeout(t) ((t)->rt.timeout)
++#endif /* !CONFIG_SCHED_ALT */
++
+ static inline struct pid *task_pid(struct task_struct *task)
+ {
+ return task->thread_pid;
+diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h
+index 1aff00b65f3c..179d77c8360e 100644
+--- a/include/linux/sched/deadline.h
++++ b/include/linux/sched/deadline.h
+@@ -1,5 +1,24 @@
+ /* SPDX-License-Identifier: GPL-2.0 */
+
++#ifdef CONFIG_SCHED_ALT
++
++static inline int dl_task(struct task_struct *p)
++{
++ return 0;
++}
++
++#ifdef CONFIG_SCHED_BMQ
++#define __tsk_deadline(p) (0UL)
++#endif
++
++#ifdef CONFIG_SCHED_PDS
++#define __tsk_deadline(p) ((p)->priodl)
++#endif
++
++#else
++
++#define __tsk_deadline(p) ((p)->dl.deadline)
++
+ /*
+ * SCHED_DEADLINE tasks has negative priorities, reflecting
+ * the fact that any of them has higher prio than RT and
+@@ -19,6 +38,7 @@ static inline int dl_task(struct task_struct *p)
+ {
+ return dl_prio(p->prio);
+ }
++#endif /* CONFIG_SCHED_ALT */
+
+ static inline bool dl_time_before(u64 a, u64 b)
+ {
+diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
+index ab83d85e1183..4d4f92bffeea 100644
+--- a/include/linux/sched/prio.h
++++ b/include/linux/sched/prio.h
+@@ -18,6 +18,14 @@
+ #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH)
+ #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2)
+
++/* +/- priority levels from the base priority */
++#ifdef CONFIG_SCHED_BMQ
++#define MAX_PRIORITY_ADJ 7
++#endif
++#ifdef CONFIG_SCHED_PDS
++#define MAX_PRIORITY_ADJ 0
++#endif
++
+ /*
+ * Convert user-nice values [ -20 ... 0 ... 19 ]
+ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
+diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h
+index e5af028c08b4..0a7565d0d3cf 100644
+--- a/include/linux/sched/rt.h
++++ b/include/linux/sched/rt.h
+@@ -24,8 +24,10 @@ static inline bool task_is_realtime(struct task_struct *tsk)
+
+ if (policy == SCHED_FIFO || policy == SCHED_RR)
+ return true;
++#ifndef CONFIG_SCHED_ALT
+ if (policy == SCHED_DEADLINE)
+ return true;
++#endif
+ return false;
+ }
+
+diff --git a/include/linux/skip_list.h b/include/linux/skip_list.h
+new file mode 100644
+index 000000000000..637c83ecbd6b
+--- /dev/null
++++ b/include/linux/skip_list.h
+@@ -0,0 +1,175 @@
++/*
++ * Copyright (C) 2016 Alfred Chen.
++ *
++ * Code based on Con Kolivas's skip list implementation for BFS, and
++ * which is based on example originally by William Pugh.
++ *
++ * Skip Lists are a probabilistic alternative to balanced trees, as
++ * described in the June 1990 issue of CACM and were invented by
++ * William Pugh in 1987.
++ *
++ * A couple of comments about this implementation:
++ *
++ * This file only provides a infrastructure of skip list.
++ *
++ * skiplist_node is embedded into container data structure, to get rid
++ * the dependency of kmalloc/kfree operation in scheduler code.
++ *
++ * A customized search function should be defined using DEFINE_SKIPLIST_INSERT
++ * macro and be used for skip list insert operation.
++ *
++ * Random Level is also not defined in this file, instead, it should be
++ * customized implemented and set to node->level then pass to the customized
++ * skiplist_insert function.
++ *
++ * Levels start at zero and go up to (NUM_SKIPLIST_LEVEL -1)
++ *
++ * NUM_SKIPLIST_LEVEL in this implementation is 8 instead of origin 16,
++ * considering that there will be 256 entries to enable the top level when using
++ * random level p=0.5, and that number is more than enough for a run queue usage
++ * in a scheduler usage. And it also help to reduce the memory usage of the
++ * embedded skip list node in task_struct to about 50%.
++ *
++ * The insertion routine has been implemented so as to use the
++ * dirty hack described in the CACM paper: if a random level is
++ * generated that is more than the current maximum level, the
++ * current maximum level plus one is used instead.
++ *
++ * BFS Notes: In this implementation of skiplists, there are bidirectional
++ * next/prev pointers and the insert function returns a pointer to the actual
++ * node the value is stored. The key here is chosen by the scheduler so as to
++ * sort tasks according to the priority list requirements and is no longer used
++ * by the scheduler after insertion. The scheduler lookup, however, occurs in
++ * O(1) time because it is always the first item in the level 0 linked list.
++ * Since the task struct stores a copy of the node pointer upon skiplist_insert,
++ * it can also remove it much faster than the original implementation with the
++ * aid of prev<->next pointer manipulation and no searching.
++ */
++#ifndef _LINUX_SKIP_LIST_H
++#define _LINUX_SKIP_LIST_H
++
++#include <linux/kernel.h>
++
++#define NUM_SKIPLIST_LEVEL (4)
++
++struct skiplist_node {
++ int level; /* Levels in this node */
++ struct skiplist_node *next[NUM_SKIPLIST_LEVEL];
++ struct skiplist_node *prev[NUM_SKIPLIST_LEVEL];
++};
++
++#define SKIPLIST_NODE_INIT(name) { 0,\
++ {&name, &name, &name, &name},\
++ {&name, &name, &name, &name},\
++ }
++
++/**
++ * INIT_SKIPLIST_NODE -- init a skiplist_node, expecially for header
++ * @node: the skip list node to be inited.
++ */
++static inline void INIT_SKIPLIST_NODE(struct skiplist_node *node)
++{
++ int i;
++
++ node->level = 0;
++ for (i = 0; i < NUM_SKIPLIST_LEVEL; i++) {
++ WRITE_ONCE(node->next[i], node);
++ node->prev[i] = node;
++ }
++}
++
++/**
++ * skiplist_entry - get the struct for this entry
++ * @ptr: the &struct skiplist_node pointer.
++ * @type: the type of the struct this is embedded in.
++ * @member: the name of the skiplist_node within the struct.
++ */
++#define skiplist_entry(ptr, type, member) \
++ container_of(ptr, type, member)
++
++/**
++ * DEFINE_SKIPLIST_INSERT_FUNC -- macro to define a customized skip list insert
++ * function, which takes two parameters, first one is the header node of the
++ * skip list, second one is the skip list node to be inserted
++ * @func_name: the customized skip list insert function name
++ * @search_func: the search function to be used, which takes two parameters,
++ * 1st one is the itrator of skiplist_node in the list, the 2nd is the skip list
++ * node to be inserted, the function should return true if search should be
++ * continued, otherwise return false.
++ * Returns 1 if @node is inserted as the first item of skip list at level zero,
++ * otherwise 0
++ */
++#define DEFINE_SKIPLIST_INSERT_FUNC(func_name, search_func)\
++static inline int func_name(struct skiplist_node *head, struct skiplist_node *node)\
++{\
++ struct skiplist_node *p, *q;\
++ unsigned int k = head->level;\
++ unsigned int l = node->level;\
++\
++ p = head;\
++ if (l > k) {\
++ l = node->level = ++head->level;\
++\
++ node->next[l] = head;\
++ node->prev[l] = head;\
++ head->next[l] = node;\
++ head->prev[l] = node;\
++\
++ do {\
++ while (q = p->next[k], q != head && search_func(q, node))\
++ p = q;\
++\
++ node->prev[k] = p;\
++ node->next[k] = q;\
++ q->prev[k] = node;\
++ p->next[k] = node;\
++ } while (k--);\
++\
++ return (p == head);\
++ }\
++\
++ while (k > l) {\
++ while (q = p->next[k], q != head && search_func(q, node))\
++ p = q;\
++ k--;\
++ }\
++\
++ do {\
++ while (q = p->next[k], q != head && search_func(q, node))\
++ p = q;\
++\
++ node->prev[k] = p;\
++ node->next[k] = q;\
++ q->prev[k] = node;\
++ p->next[k] = node;\
++ } while (k--);\
++\
++ return (p == head);\
++}
++
++/**
++ * skiplist_del_init -- delete skip list node from a skip list and reset it's
++ * init state
++ * @head: the header node of the skip list to be deleted from.
++ * @node: the skip list node to be deleted, the caller need to ensure @node is
++ * in skip list which @head represent.
++ * Returns 1 if @node is the first item of skip level at level zero, otherwise 0
++ */
++static inline int
++skiplist_del_init(struct skiplist_node *head, struct skiplist_node *node)
++{
++ unsigned int i, level = node->level;
++
++ for (i = 0; i <= level; i++) {
++ node->prev[i]->next[i] = node->next[i];
++ node->next[i]->prev[i] = node->prev[i];
++ }
++ if (level == head->level && level) {
++ while (head->next[level] == head && level)
++ level--;
++ head->level = level;
++ }
++
++ return (node->prev[0] == head);
++}
++#endif /* _LINUX_SKIP_LIST_H */
+diff --git a/init/Kconfig b/init/Kconfig
+index 5f5c776ef192..2529408ce0b5 100644
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -779,9 +779,39 @@ config GENERIC_SCHED_CLOCK
+
+ menu "Scheduler features"
+
++menuconfig SCHED_ALT
++ bool "Alternative CPU Schedulers"
++ default y
++ help
++ This feature enable alternative CPU scheduler"
++
++if SCHED_ALT
++
++choice
++ prompt "Alternative CPU Scheduler"
++ default SCHED_BMQ
++
++config SCHED_BMQ
++ bool "BMQ CPU scheduler"
++ help
++ The BitMap Queue CPU scheduler for excellent interactivity and
++ responsiveness on the desktop and solid scalability on normal
++ hardware and commodity servers.
++
++config SCHED_PDS
++ bool "PDS CPU scheduler"
++ help
++ The Priority and Deadline based Skip list multiple queue CPU
++ Scheduler.
++
++endchoice
++
++endif
++
+ config UCLAMP_TASK
+ bool "Enable utilization clamping for RT/FAIR tasks"
+ depends on CPU_FREQ_GOV_SCHEDUTIL
++ depends on !SCHED_ALT
+ help
+ This feature enables the scheduler to track the clamped utilization
+ of each CPU based on RUNNABLE tasks scheduled on that CPU.
+@@ -867,6 +897,7 @@ config NUMA_BALANCING
+ depends on ARCH_SUPPORTS_NUMA_BALANCING
+ depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
+ depends on SMP && NUMA && MIGRATION
++ depends on !SCHED_ALT
+ help
+ This option adds support for automatic NUMA aware memory/task placement.
+ The mechanism is quite primitive and is based on migrating memory when
+@@ -959,6 +990,7 @@ config FAIR_GROUP_SCHED
+ depends on CGROUP_SCHED
+ default CGROUP_SCHED
+
++if !SCHED_ALT
+ config CFS_BANDWIDTH
+ bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
+ depends on FAIR_GROUP_SCHED
+@@ -981,6 +1013,7 @@ config RT_GROUP_SCHED
+ realtime bandwidth for them.
+ See Documentation/scheduler/sched-rt-group.rst for more information.
+
++endif #!SCHED_ALT
+ endif #CGROUP_SCHED
+
+ config UCLAMP_TASK_GROUP
+@@ -1210,6 +1243,7 @@ config CHECKPOINT_RESTORE
+
+ config SCHED_AUTOGROUP
+ bool "Automatic process group scheduling"
++ depends on !SCHED_ALT
+ select CGROUPS
+ select CGROUP_SCHED
+ select FAIR_GROUP_SCHED
+diff --git a/init/init_task.c b/init/init_task.c
+index 3711cdaafed2..47f57d2cc488 100644
+--- a/init/init_task.c
++++ b/init/init_task.c
+@@ -75,9 +75,20 @@ struct task_struct init_task
+ .stack = init_stack,
+ .usage = REFCOUNT_INIT(2),
+ .flags = PF_KTHREAD,
++#ifdef CONFIG_SCHED_BMQ
++ .prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ,
++ .static_prio = DEFAULT_PRIO,
++ .normal_prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ,
++#endif
++#ifdef CONFIG_SCHED_PDS
++ .prio = MAX_RT_PRIO,
++ .static_prio = DEFAULT_PRIO,
++ .normal_prio = MAX_RT_PRIO,
++#else
+ .prio = MAX_PRIO - 20,
+ .static_prio = MAX_PRIO - 20,
+ .normal_prio = MAX_PRIO - 20,
++#endif
+ .policy = SCHED_NORMAL,
+ .cpus_ptr = &init_task.cpus_mask,
+ .cpus_mask = CPU_MASK_ALL,
+@@ -87,6 +98,19 @@ struct task_struct init_task
+ .restart_block = {
+ .fn = do_no_restart_syscall,
+ },
++#ifdef CONFIG_SCHED_ALT
++#ifdef CONFIG_SCHED_BMQ
++ .boost_prio = 0,
++ .bmq_idx = 15,
++ .bmq_node = LIST_HEAD_INIT(init_task.bmq_node),
++#endif
++#ifdef CONFIG_SCHED_PDS
++ .deadline = 0,
++ .sl_level = 0,
++ .sl_node = SKIPLIST_NODE_INIT(init_task.sl_node),
++#endif
++ .time_slice = HZ,
++#else
+ .se = {
+ .group_node = LIST_HEAD_INIT(init_task.se.group_node),
+ },
+@@ -94,6 +118,7 @@ struct task_struct init_task
+ .run_list = LIST_HEAD_INIT(init_task.rt.run_list),
+ .time_slice = RR_TIMESLICE,
+ },
++#endif
+ .tasks = LIST_HEAD_INIT(init_task.tasks),
+ #ifdef CONFIG_SMP
+ .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
+diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
+index 5258b68153e0..3eb670b1bb76 100644
+--- a/kernel/cgroup/cpuset.c
++++ b/kernel/cgroup/cpuset.c
+@@ -636,7 +636,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
+ return ret;
+ }
+
+-#ifdef CONFIG_SMP
++#if defined(CONFIG_SMP) && !defined(CONFIG_SCHED_ALT)
+ /*
+ * Helper routine for generate_sched_domains().
+ * Do cpusets a, b have overlapping effective cpus_allowed masks?
+@@ -1032,7 +1032,7 @@ static void rebuild_sched_domains_locked(void)
+ /* Have scheduler rebuild the domains */
+ partition_and_rebuild_sched_domains(ndoms, doms, attr);
+ }
+-#else /* !CONFIG_SMP */
++#else /* !CONFIG_SMP || CONFIG_SCHED_ALT */
+ static void rebuild_sched_domains_locked(void)
+ {
+ }
+diff --git a/kernel/delayacct.c b/kernel/delayacct.c
+index 27725754ac99..769d773c7182 100644
+--- a/kernel/delayacct.c
++++ b/kernel/delayacct.c
+@@ -106,7 +106,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
+ */
+ t1 = tsk->sched_info.pcount;
+ t2 = tsk->sched_info.run_delay;
+- t3 = tsk->se.sum_exec_runtime;
++ t3 = tsk_seruntime(tsk);
+
+ d->cpu_count += t1;
+
+diff --git a/kernel/exit.c b/kernel/exit.c
+index 04029e35e69a..5ee0dc0b9175 100644
+--- a/kernel/exit.c
++++ b/kernel/exit.c
+@@ -122,7 +122,7 @@ static void __exit_signal(struct task_struct *tsk)
+ sig->curr_target = next_thread(tsk);
+ }
+
+- add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
++ add_device_randomness((const void*) &tsk_seruntime(tsk),
+ sizeof(unsigned long long));
+
+ /*
+@@ -143,7 +143,7 @@ static void __exit_signal(struct task_struct *tsk)
+ sig->inblock += task_io_get_inblock(tsk);
+ sig->oublock += task_io_get_oublock(tsk);
+ task_io_accounting_add(&sig->ioac, &tsk->ioac);
+- sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
++ sig->sum_sched_runtime += tsk_seruntime(tsk);
+ sig->nr_threads--;
+ __unhash_process(tsk, group_dead);
+ write_sequnlock(&sig->stats_lock);
+diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
+index f6310f848f34..4176ad070bc9 100644
+--- a/kernel/livepatch/transition.c
++++ b/kernel/livepatch/transition.c
+@@ -306,7 +306,11 @@ static bool klp_try_switch_task(struct task_struct *task)
+ */
+ rq = task_rq_lock(task, &flags);
+
++#ifdef CONFIG_SCHED_ALT
++ if (task_running(task) && task != current) {
++#else
+ if (task_running(rq, task) && task != current) {
++#endif
+ snprintf(err_buf, STACK_ERR_BUF_SIZE,
+ "%s: %s:%d is running\n", __func__, task->comm,
+ task->pid);
+diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
+index 48fff6437901..40506d5b5a2e 100644
+--- a/kernel/locking/rtmutex.c
++++ b/kernel/locking/rtmutex.c
+@@ -227,15 +227,19 @@ static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock,
+ * Only use with rt_mutex_waiter_{less,equal}()
+ */
+ #define task_to_waiter(p) \
+- &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline }
++ &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = __tsk_deadline(p) }
+
+ static inline int
+ rt_mutex_waiter_less(struct rt_mutex_waiter *left,
+ struct rt_mutex_waiter *right)
+ {
++#ifdef CONFIG_SCHED_PDS
++ return (left->deadline < right->deadline);
++#else
+ if (left->prio < right->prio)
+ return 1;
+
++#ifndef CONFIG_SCHED_BMQ
+ /*
+ * If both waiters have dl_prio(), we check the deadlines of the
+ * associated tasks.
+@@ -244,17 +248,23 @@ rt_mutex_waiter_less(struct rt_mutex_waiter *left,
+ */
+ if (dl_prio(left->prio))
+ return dl_time_before(left->deadline, right->deadline);
++#endif
+
+ return 0;
++#endif
+ }
+
+ static inline int
+ rt_mutex_waiter_equal(struct rt_mutex_waiter *left,
+ struct rt_mutex_waiter *right)
+ {
++#ifdef CONFIG_SCHED_PDS
++ return (left->deadline == right->deadline);
++#else
+ if (left->prio != right->prio)
+ return 0;
+
++#ifndef CONFIG_SCHED_BMQ
+ /*
+ * If both waiters have dl_prio(), we check the deadlines of the
+ * associated tasks.
+@@ -263,8 +273,10 @@ rt_mutex_waiter_equal(struct rt_mutex_waiter *left,
+ */
+ if (dl_prio(left->prio))
+ return left->deadline == right->deadline;
++#endif
+
+ return 1;
++#endif
+ }
+
+ #define __node_2_waiter(node) \
+@@ -660,7 +672,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ * the values of the node being removed.
+ */
+ waiter->prio = task->prio;
+- waiter->deadline = task->dl.deadline;
++ waiter->deadline = __tsk_deadline(task);
+
+ rt_mutex_enqueue(lock, waiter);
+
+@@ -933,7 +945,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ waiter->task = task;
+ waiter->lock = lock;
+ waiter->prio = task->prio;
+- waiter->deadline = task->dl.deadline;
++ waiter->deadline = __tsk_deadline(task);
+
+ /* Get the top priority waiter on the lock */
+ if (rt_mutex_has_waiters(lock))
+diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
+index 5fc9c9b70862..eb6d7d87779f 100644
+--- a/kernel/sched/Makefile
++++ b/kernel/sched/Makefile
+@@ -22,14 +22,20 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
+ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
+ endif
+
+-obj-y += core.o loadavg.o clock.o cputime.o
+-obj-y += idle.o fair.o rt.o deadline.o
+-obj-y += wait.o wait_bit.o swait.o completion.o
+-
+-obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o
++ifdef CONFIG_SCHED_ALT
++obj-y += alt_core.o alt_debug.o
++else
++obj-y += core.o
++obj-y += fair.o rt.o deadline.o
++obj-$(CONFIG_SMP) += cpudeadline.o stop_task.o
+ obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o
+-obj-$(CONFIG_SCHEDSTATS) += stats.o
+ obj-$(CONFIG_SCHED_DEBUG) += debug.o
++endif
++obj-y += loadavg.o clock.o cputime.o
++obj-y += idle.o
++obj-y += wait.o wait_bit.o swait.o completion.o
++obj-$(CONFIG_SMP) += cpupri.o pelt.o topology.o
++obj-$(CONFIG_SCHEDSTATS) += stats.o
+ obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
+ obj-$(CONFIG_CPU_FREQ) += cpufreq.o
+ obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o
+diff --git a/kernel/sched/alt_core.c b/kernel/sched/alt_core.c
+new file mode 100644
+index 000000000000..f69ed4d89395
+--- /dev/null
++++ b/kernel/sched/alt_core.c
+@@ -0,0 +1,7149 @@
++/*
++ * kernel/sched/alt_core.c
++ *
++ * Core alternative kernel scheduler code and related syscalls
++ *
++ * Copyright (C) 1991-2002 Linus Torvalds
++ *
++ * 2009-08-13 Brainfuck deadline scheduling policy by Con Kolivas deletes
++ * a whole lot of those previous things.
++ * 2017-09-06 Priority and Deadline based Skip list multiple queue kernel
++ * scheduler by Alfred Chen.
++ * 2019-02-20 BMQ(BitMap Queue) kernel scheduler by Alfred Chen.
++ */
++#define CREATE_TRACE_POINTS
++#include <trace/events/sched.h>
++#undef CREATE_TRACE_POINTS
++
++#include "sched.h"
++
++#include <linux/sched/rt.h>
++
++#include <linux/context_tracking.h>
++#include <linux/compat.h>
++#include <linux/blkdev.h>
++#include <linux/delayacct.h>
++#include <linux/freezer.h>
++#include <linux/init_task.h>
++#include <linux/kprobes.h>
++#include <linux/mmu_context.h>
++#include <linux/nmi.h>
++#include <linux/profile.h>
++#include <linux/rcupdate_wait.h>
++#include <linux/security.h>
++#include <linux/syscalls.h>
++#include <linux/wait_bit.h>
++
++#include <linux/kcov.h>
++#include <linux/scs.h>
++
++#include <asm/switch_to.h>
++
++#include "../workqueue_internal.h"
++#include "../../fs/io-wq.h"
++#include "../smpboot.h"
++
++#include "pelt.h"
++#include "smp.h"
++
++/*
++ * Export tracepoints that act as a bare tracehook (ie: have no trace event
++ * associated with them) to allow external modules to probe them.
++ */
++EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp);
++
++#define ALT_SCHED_VERSION "v5.11-r3"
++
++/* rt_prio(prio) defined in include/linux/sched/rt.h */
++#define rt_task(p) rt_prio((p)->prio)
++#define rt_policy(policy) ((policy) == SCHED_FIFO || (policy) == SCHED_RR)
++#define task_has_rt_policy(p) (rt_policy((p)->policy))
++
++#define STOP_PRIO (MAX_RT_PRIO - 1)
++
++/* Default time slice is 4 in ms, can be set via kernel parameter "sched_timeslice" */
++u64 sched_timeslice_ns __read_mostly = (4 * 1000 * 1000);
++
++static int __init sched_timeslice(char *str)
++{
++ int timeslice_us;
++
++ get_option(&str, ×lice_us);
++ if (timeslice_us >= 1000)
++ sched_timeslice_ns = timeslice_us * 1000;
++
++ return 0;
++}
++early_param("sched_timeslice", sched_timeslice);
++
++/* Reschedule if less than this many μs left */
++#define RESCHED_NS (100 * 1000)
++
++/**
++ * sched_yield_type - Choose what sort of yield sched_yield will perform.
++ * 0: No yield.
++ * 1: Deboost and requeue task. (default)
++ * 2: Set rq skip task.
++ */
++int sched_yield_type __read_mostly = 1;
++
++#ifdef CONFIG_SMP
++static cpumask_t sched_rq_pending_mask ____cacheline_aligned_in_smp;
++
++DEFINE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_affinity_masks);
++DEFINE_PER_CPU(cpumask_t *, sched_cpu_affinity_end_mask);
++
++DEFINE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks);
++DEFINE_PER_CPU(cpumask_t *, sched_cpu_llc_mask);
++
++#ifdef CONFIG_SCHED_SMT
++DEFINE_STATIC_KEY_FALSE(sched_smt_present);
++EXPORT_SYMBOL_GPL(sched_smt_present);
++#endif
++
++/*
++ * Keep a unique ID per domain (we use the first CPUs number in the cpumask of
++ * the domain), this allows us to quickly tell if two cpus are in the same cache
++ * domain, see cpus_share_cache().
++ */
++DEFINE_PER_CPU(int, sd_llc_id);
++#endif /* CONFIG_SMP */
++
++static DEFINE_MUTEX(sched_hotcpu_mutex);
++
++DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
++
++#ifndef prepare_arch_switch
++# define prepare_arch_switch(next) do { } while (0)
++#endif
++#ifndef finish_arch_post_lock_switch
++# define finish_arch_post_lock_switch() do { } while (0)
++#endif
++
++#define IDLE_WM (IDLE_TASK_SCHED_PRIO)
++
++#ifdef CONFIG_SCHED_SMT
++static cpumask_t sched_sg_idle_mask ____cacheline_aligned_in_smp;
++#endif
++static cpumask_t sched_rq_watermark[SCHED_BITS] ____cacheline_aligned_in_smp;
++
++#ifdef CONFIG_SCHED_BMQ
++#include "bmq_imp.h"
++#endif
++#ifdef CONFIG_SCHED_PDS
++#include "pds_imp.h"
++#endif
++
++static inline void update_sched_rq_watermark(struct rq *rq)
++{
++ unsigned long watermark = sched_queue_watermark(rq);
++ unsigned long last_wm = rq->watermark;
++ unsigned long i;
++ int cpu;
++
++ /*printk(KERN_INFO "sched: watermark(%d) %d, last %d\n",
++ cpu_of(rq), watermark, last_wm);*/
++ if (watermark == last_wm)
++ return;
++
++ rq->watermark = watermark;
++ cpu = cpu_of(rq);
++ if (watermark < last_wm) {
++ for (i = watermark + 1; i <= last_wm; i++)
++ cpumask_andnot(&sched_rq_watermark[i],
++ &sched_rq_watermark[i], cpumask_of(cpu));
++#ifdef CONFIG_SCHED_SMT
++ if (!static_branch_likely(&sched_smt_present))
++ return;
++ if (IDLE_WM == last_wm)
++ cpumask_andnot(&sched_sg_idle_mask,
++ &sched_sg_idle_mask, cpu_smt_mask(cpu));
++#endif
++ return;
++ }
++ /* last_wm < watermark */
++ for (i = last_wm + 1; i <= watermark; i++)
++ cpumask_set_cpu(cpu, &sched_rq_watermark[i]);
++#ifdef CONFIG_SCHED_SMT
++ if (!static_branch_likely(&sched_smt_present))
++ return;
++ if (IDLE_WM == watermark) {
++ cpumask_t tmp;
++ cpumask_and(&tmp, cpu_smt_mask(cpu), &sched_rq_watermark[IDLE_WM]);
++ if (cpumask_equal(&tmp, cpu_smt_mask(cpu)))
++ cpumask_or(&sched_sg_idle_mask, cpu_smt_mask(cpu),
++ &sched_sg_idle_mask);
++ }
++#endif
++}
++
++static inline struct task_struct *rq_runnable_task(struct rq *rq)
++{
++ struct task_struct *next = sched_rq_first_task(rq);
++
++ if (unlikely(next == rq->skip))
++ next = sched_rq_next_task(next, rq);
++
++ return next;
++}
++
++/*
++ * Serialization rules:
++ *
++ * Lock order:
++ *
++ * p->pi_lock
++ * rq->lock
++ * hrtimer_cpu_base->lock (hrtimer_start() for bandwidth controls)
++ *
++ * rq1->lock
++ * rq2->lock where: rq1 < rq2
++ *
++ * Regular state:
++ *
++ * Normal scheduling state is serialized by rq->lock. __schedule() takes the
++ * local CPU's rq->lock, it optionally removes the task from the runqueue and
++ * always looks at the local rq data structures to find the most eligible task
++ * to run next.
++ *
++ * Task enqueue is also under rq->lock, possibly taken from another CPU.
++ * Wakeups from another LLC domain might use an IPI to transfer the enqueue to
++ * the local CPU to avoid bouncing the runqueue state around [ see
++ * ttwu_queue_wakelist() ]
++ *
++ * Task wakeup, specifically wakeups that involve migration, are horribly
++ * complicated to avoid having to take two rq->locks.
++ *
++ * Special state:
++ *
++ * System-calls and anything external will use task_rq_lock() which acquires
++ * both p->pi_lock and rq->lock. As a consequence the state they change is
++ * stable while holding either lock:
++ *
++ * - sched_setaffinity()/
++ * set_cpus_allowed_ptr(): p->cpus_ptr, p->nr_cpus_allowed
++ * - set_user_nice(): p->se.load, p->*prio
++ * - __sched_setscheduler(): p->sched_class, p->policy, p->*prio,
++ * p->se.load, p->rt_priority,
++ * p->dl.dl_{runtime, deadline, period, flags, bw, density}
++ * - sched_setnuma(): p->numa_preferred_nid
++ * - sched_move_task()/
++ * cpu_cgroup_fork(): p->sched_task_group
++ * - uclamp_update_active() p->uclamp*
++ *
++ * p->state <- TASK_*:
++ *
++ * is changed locklessly using set_current_state(), __set_current_state() or
++ * set_special_state(), see their respective comments, or by
++ * try_to_wake_up(). This latter uses p->pi_lock to serialize against
++ * concurrent self.
++ *
++ * p->on_rq <- { 0, 1 = TASK_ON_RQ_QUEUED, 2 = TASK_ON_RQ_MIGRATING }:
++ *
++ * is set by activate_task() and cleared by deactivate_task(), under
++ * rq->lock. Non-zero indicates the task is runnable, the special
++ * ON_RQ_MIGRATING state is used for migration without holding both
++ * rq->locks. It indicates task_cpu() is not stable, see task_rq_lock().
++ *
++ * p->on_cpu <- { 0, 1 }:
++ *
++ * is set by prepare_task() and cleared by finish_task() such that it will be
++ * set before p is scheduled-in and cleared after p is scheduled-out, both
++ * under rq->lock. Non-zero indicates the task is running on its CPU.
++ *
++ * [ The astute reader will observe that it is possible for two tasks on one
++ * CPU to have ->on_cpu = 1 at the same time. ]
++ *
++ * task_cpu(p): is changed by set_task_cpu(), the rules are:
++ *
++ * - Don't call set_task_cpu() on a blocked task:
++ *
++ * We don't care what CPU we're not running on, this simplifies hotplug,
++ * the CPU assignment of blocked tasks isn't required to be valid.
++ *
++ * - for try_to_wake_up(), called under p->pi_lock:
++ *
++ * This allows try_to_wake_up() to only take one rq->lock, see its comment.
++ *
++ * - for migration called under rq->lock:
++ * [ see task_on_rq_migrating() in task_rq_lock() ]
++ *
++ * o move_queued_task()
++ * o detach_task()
++ *
++ * - for migration called under double_rq_lock():
++ *
++ * o __migrate_swap_task()
++ * o push_rt_task() / pull_rt_task()
++ * o push_dl_task() / pull_dl_task()
++ * o dl_task_offline_migration()
++ *
++ */
++
++/*
++ * Context: p->pi_lock
++ */
++static inline struct rq
++*__task_access_lock(struct task_struct *p, raw_spinlock_t **plock)
++{
++ struct rq *rq;
++ for (;;) {
++ rq = task_rq(p);
++ if (p->on_cpu || task_on_rq_queued(p)) {
++ raw_spin_lock(&rq->lock);
++ if (likely((p->on_cpu || task_on_rq_queued(p))
++ && rq == task_rq(p))) {
++ *plock = &rq->lock;
++ return rq;
++ }
++ raw_spin_unlock(&rq->lock);
++ } else if (task_on_rq_migrating(p)) {
++ do {
++ cpu_relax();
++ } while (unlikely(task_on_rq_migrating(p)));
++ } else {
++ *plock = NULL;
++ return rq;
++ }
++ }
++}
++
++static inline void
++__task_access_unlock(struct task_struct *p, raw_spinlock_t *lock)
++{
++ if (NULL != lock)
++ raw_spin_unlock(lock);
++}
++
++static inline struct rq
++*task_access_lock_irqsave(struct task_struct *p, raw_spinlock_t **plock,
++ unsigned long *flags)
++{
++ struct rq *rq;
++ for (;;) {
++ rq = task_rq(p);
++ if (p->on_cpu || task_on_rq_queued(p)) {
++ raw_spin_lock_irqsave(&rq->lock, *flags);
++ if (likely((p->on_cpu || task_on_rq_queued(p))
++ && rq == task_rq(p))) {
++ *plock = &rq->lock;
++ return rq;
++ }
++ raw_spin_unlock_irqrestore(&rq->lock, *flags);
++ } else if (task_on_rq_migrating(p)) {
++ do {
++ cpu_relax();
++ } while (unlikely(task_on_rq_migrating(p)));
++ } else {
++ raw_spin_lock_irqsave(&p->pi_lock, *flags);
++ if (likely(!p->on_cpu && !p->on_rq &&
++ rq == task_rq(p))) {
++ *plock = &p->pi_lock;
++ return rq;
++ }
++ raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
++ }
++ }
++}
++
++static inline void
++task_access_unlock_irqrestore(struct task_struct *p, raw_spinlock_t *lock,
++ unsigned long *flags)
++{
++ raw_spin_unlock_irqrestore(lock, *flags);
++}
++
++/*
++ * __task_rq_lock - lock the rq @p resides on.
++ */
++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
++ __acquires(rq->lock)
++{
++ struct rq *rq;
++
++ lockdep_assert_held(&p->pi_lock);
++
++ for (;;) {
++ rq = task_rq(p);
++ raw_spin_lock(&rq->lock);
++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p)))
++ return rq;
++ raw_spin_unlock(&rq->lock);
++
++ while (unlikely(task_on_rq_migrating(p)))
++ cpu_relax();
++ }
++}
++
++/*
++ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
++ */
++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
++ __acquires(p->pi_lock)
++ __acquires(rq->lock)
++{
++ struct rq *rq;
++
++ for (;;) {
++ raw_spin_lock_irqsave(&p->pi_lock, rf->flags);
++ rq = task_rq(p);
++ raw_spin_lock(&rq->lock);
++ /*
++ * move_queued_task() task_rq_lock()
++ *
++ * ACQUIRE (rq->lock)
++ * [S] ->on_rq = MIGRATING [L] rq = task_rq()
++ * WMB (__set_task_cpu()) ACQUIRE (rq->lock);
++ * [S] ->cpu = new_cpu [L] task_rq()
++ * [L] ->on_rq
++ * RELEASE (rq->lock)
++ *
++ * If we observe the old CPU in task_rq_lock(), the acquire of
++ * the old rq->lock will fully serialize against the stores.
++ *
++ * If we observe the new CPU in task_rq_lock(), the address
++ * dependency headed by '[L] rq = task_rq()' and the acquire
++ * will pair with the WMB to ensure we then also see migrating.
++ */
++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
++ return rq;
++ }
++ raw_spin_unlock(&rq->lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
++
++ while (unlikely(task_on_rq_migrating(p)))
++ cpu_relax();
++ }
++}
++
++static inline void
++rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
++ __acquires(rq->lock)
++{
++ raw_spin_lock_irqsave(&rq->lock, rf->flags);
++}
++
++static inline void
++rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf)
++ __releases(rq->lock)
++{
++ raw_spin_unlock_irqrestore(&rq->lock, rf->flags);
++}
++
++/*
++ * RQ-clock updating methods:
++ */
++
++static void update_rq_clock_task(struct rq *rq, s64 delta)
++{
++/*
++ * In theory, the compile should just see 0 here, and optimize out the call
++ * to sched_rt_avg_update. But I don't trust it...
++ */
++ s64 __maybe_unused steal = 0, irq_delta = 0;
++
++#ifdef CONFIG_IRQ_TIME_ACCOUNTING
++ irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
++
++ /*
++ * Since irq_time is only updated on {soft,}irq_exit, we might run into
++ * this case when a previous update_rq_clock() happened inside a
++ * {soft,}irq region.
++ *
++ * When this happens, we stop ->clock_task and only update the
++ * prev_irq_time stamp to account for the part that fit, so that a next
++ * update will consume the rest. This ensures ->clock_task is
++ * monotonic.
++ *
++ * It does however cause some slight miss-attribution of {soft,}irq
++ * time, a more accurate solution would be to update the irq_time using
++ * the current rq->clock timestamp, except that would require using
++ * atomic ops.
++ */
++ if (irq_delta > delta)
++ irq_delta = delta;
++
++ rq->prev_irq_time += irq_delta;
++ delta -= irq_delta;
++#endif
++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
++ if (static_key_false((¶virt_steal_rq_enabled))) {
++ steal = paravirt_steal_clock(cpu_of(rq));
++ steal -= rq->prev_steal_time_rq;
++
++ if (unlikely(steal > delta))
++ steal = delta;
++
++ rq->prev_steal_time_rq += steal;
++ delta -= steal;
++ }
++#endif
++
++ rq->clock_task += delta;
++
++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
++ if ((irq_delta + steal))
++ update_irq_load_avg(rq, irq_delta + steal);
++#endif
++}
++
++static inline void update_rq_clock(struct rq *rq)
++{
++ s64 delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
++
++ if (unlikely(delta <= 0))
++ return;
++ rq->clock += delta;
++ update_rq_clock_task(rq, delta);
++}
++
++#ifdef CONFIG_NO_HZ_FULL
++/*
++ * Tick may be needed by tasks in the runqueue depending on their policy and
++ * requirements. If tick is needed, lets send the target an IPI to kick it out
++ * of nohz mode if necessary.
++ */
++static inline void sched_update_tick_dependency(struct rq *rq)
++{
++ int cpu = cpu_of(rq);
++
++ if (!tick_nohz_full_cpu(cpu))
++ return;
++
++ if (rq->nr_running < 2)
++ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
++ else
++ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
++}
++#else /* !CONFIG_NO_HZ_FULL */
++static inline void sched_update_tick_dependency(struct rq *rq) { }
++#endif
++
++/*
++ * Add/Remove/Requeue task to/from the runqueue routines
++ * Context: rq->lock
++ */
++static inline void dequeue_task(struct task_struct *p, struct rq *rq, int flags)
++{
++ lockdep_assert_held(&rq->lock);
++
++ /*printk(KERN_INFO "sched: dequeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/
++ WARN_ONCE(task_rq(p) != rq, "sched: dequeue task reside on cpu%d from cpu%d\n",
++ task_cpu(p), cpu_of(rq));
++
++ __SCHED_DEQUEUE_TASK(p, rq, flags, update_sched_rq_watermark(rq));
++ --rq->nr_running;
++#ifdef CONFIG_SMP
++ if (1 == rq->nr_running)
++ cpumask_clear_cpu(cpu_of(rq), &sched_rq_pending_mask);
++#endif
++
++ sched_update_tick_dependency(rq);
++}
++
++static inline void enqueue_task(struct task_struct *p, struct rq *rq, int flags)
++{
++ lockdep_assert_held(&rq->lock);
++
++ /*printk(KERN_INFO "sched: enqueue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/
++ WARN_ONCE(task_rq(p) != rq, "sched: enqueue task reside on cpu%d to cpu%d\n",
++ task_cpu(p), cpu_of(rq));
++
++ __SCHED_ENQUEUE_TASK(p, rq, flags);
++ update_sched_rq_watermark(rq);
++ ++rq->nr_running;
++#ifdef CONFIG_SMP
++ if (2 == rq->nr_running)
++ cpumask_set_cpu(cpu_of(rq), &sched_rq_pending_mask);
++#endif
++
++ sched_update_tick_dependency(rq);
++}
++
++static inline void requeue_task(struct task_struct *p, struct rq *rq)
++{
++ lockdep_assert_held(&rq->lock);
++ /*printk(KERN_INFO "sched: requeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/
++ WARN_ONCE(task_rq(p) != rq, "sched: cpu[%d] requeue task reside on cpu%d\n",
++ cpu_of(rq), task_cpu(p));
++
++ __SCHED_REQUEUE_TASK(p, rq, update_sched_rq_watermark(rq));
++}
++
++/*
++ * cmpxchg based fetch_or, macro so it works for different integer types
++ */
++#define fetch_or(ptr, mask) \
++ ({ \
++ typeof(ptr) _ptr = (ptr); \
++ typeof(mask) _mask = (mask); \
++ typeof(*_ptr) _old, _val = *_ptr; \
++ \
++ for (;;) { \
++ _old = cmpxchg(_ptr, _val, _val | _mask); \
++ if (_old == _val) \
++ break; \
++ _val = _old; \
++ } \
++ _old; \
++})
++
++#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
++/*
++ * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
++ * this avoids any races wrt polling state changes and thereby avoids
++ * spurious IPIs.
++ */
++static bool set_nr_and_not_polling(struct task_struct *p)
++{
++ struct thread_info *ti = task_thread_info(p);
++ return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG);
++}
++
++/*
++ * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set.
++ *
++ * If this returns true, then the idle task promises to call
++ * sched_ttwu_pending() and reschedule soon.
++ */
++static bool set_nr_if_polling(struct task_struct *p)
++{
++ struct thread_info *ti = task_thread_info(p);
++ typeof(ti->flags) old, val = READ_ONCE(ti->flags);
++
++ for (;;) {
++ if (!(val & _TIF_POLLING_NRFLAG))
++ return false;
++ if (val & _TIF_NEED_RESCHED)
++ return true;
++ old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED);
++ if (old == val)
++ break;
++ val = old;
++ }
++ return true;
++}
++
++#else
++static bool set_nr_and_not_polling(struct task_struct *p)
++{
++ set_tsk_need_resched(p);
++ return true;
++}
++
++#ifdef CONFIG_SMP
++static bool set_nr_if_polling(struct task_struct *p)
++{
++ return false;
++}
++#endif
++#endif
++
++static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task)
++{
++ struct wake_q_node *node = &task->wake_q;
++
++ /*
++ * Atomically grab the task, if ->wake_q is !nil already it means
++ * it's already queued (either by us or someone else) and will get the
++ * wakeup due to that.
++ *
++ * In order to ensure that a pending wakeup will observe our pending
++ * state, even in the failed case, an explicit smp_mb() must be used.
++ */
++ smp_mb__before_atomic();
++ if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL)))
++ return false;
++
++ /*
++ * The head is context local, there can be no concurrency.
++ */
++ *head->lastp = node;
++ head->lastp = &node->next;
++ return true;
++}
++
++/**
++ * wake_q_add() - queue a wakeup for 'later' waking.
++ * @head: the wake_q_head to add @task to
++ * @task: the task to queue for 'later' wakeup
++ *
++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the
++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come
++ * instantly.
++ *
++ * This function must be used as-if it were wake_up_process(); IOW the task
++ * must be ready to be woken at this location.
++ */
++void wake_q_add(struct wake_q_head *head, struct task_struct *task)
++{
++ if (__wake_q_add(head, task))
++ get_task_struct(task);
++}
++
++/**
++ * wake_q_add_safe() - safely queue a wakeup for 'later' waking.
++ * @head: the wake_q_head to add @task to
++ * @task: the task to queue for 'later' wakeup
++ *
++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the
++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come
++ * instantly.
++ *
++ * This function must be used as-if it were wake_up_process(); IOW the task
++ * must be ready to be woken at this location.
++ *
++ * This function is essentially a task-safe equivalent to wake_q_add(). Callers
++ * that already hold reference to @task can call the 'safe' version and trust
++ * wake_q to do the right thing depending whether or not the @task is already
++ * queued for wakeup.
++ */
++void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task)
++{
++ if (!__wake_q_add(head, task))
++ put_task_struct(task);
++}
++
++void wake_up_q(struct wake_q_head *head)
++{
++ struct wake_q_node *node = head->first;
++
++ while (node != WAKE_Q_TAIL) {
++ struct task_struct *task;
++
++ task = container_of(node, struct task_struct, wake_q);
++ BUG_ON(!task);
++ /* task can safely be re-inserted now: */
++ node = node->next;
++ task->wake_q.next = NULL;
++
++ /*
++ * wake_up_process() executes a full barrier, which pairs with
++ * the queueing in wake_q_add() so as not to miss wakeups.
++ */
++ wake_up_process(task);
++ put_task_struct(task);
++ }
++}
++
++/*
++ * resched_curr - mark rq's current task 'to be rescheduled now'.
++ *
++ * On UP this means the setting of the need_resched flag, on SMP it
++ * might also involve a cross-CPU call to trigger the scheduler on
++ * the target CPU.
++ */
++void resched_curr(struct rq *rq)
++{
++ struct task_struct *curr = rq->curr;
++ int cpu;
++
++ lockdep_assert_held(&rq->lock);
++
++ if (test_tsk_need_resched(curr))
++ return;
++
++ cpu = cpu_of(rq);
++ if (cpu == smp_processor_id()) {
++ set_tsk_need_resched(curr);
++ set_preempt_need_resched();
++ return;
++ }
++
++ if (set_nr_and_not_polling(curr))
++ smp_send_reschedule(cpu);
++ else
++ trace_sched_wake_idle_without_ipi(cpu);
++}
++
++void resched_cpu(int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++ unsigned long flags;
++
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ if (cpu_online(cpu) || cpu == smp_processor_id())
++ resched_curr(cpu_rq(cpu));
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++}
++
++#ifdef CONFIG_SMP
++#ifdef CONFIG_NO_HZ_COMMON
++void nohz_balance_enter_idle(int cpu) {}
++
++void select_nohz_load_balancer(int stop_tick) {}
++
++void set_cpu_sd_state_idle(void) {}
++
++/*
++ * In the semi idle case, use the nearest busy CPU for migrating timers
++ * from an idle CPU. This is good for power-savings.
++ *
++ * We don't do similar optimization for completely idle system, as
++ * selecting an idle CPU will add more delays to the timers than intended
++ * (as that CPU's timer base may not be uptodate wrt jiffies etc).
++ */
++int get_nohz_timer_target(void)
++{
++ int i, cpu = smp_processor_id(), default_cpu = -1;
++ struct cpumask *mask;
++
++ if (housekeeping_cpu(cpu, HK_FLAG_TIMER)) {
++ if (!idle_cpu(cpu))
++ return cpu;
++ default_cpu = cpu;
++ }
++
++ for (mask = per_cpu(sched_cpu_affinity_masks, cpu) + 1;
++ mask < per_cpu(sched_cpu_affinity_end_mask, cpu); mask++)
++ for_each_cpu_and(i, mask, housekeeping_cpumask(HK_FLAG_TIMER))
++ if (!idle_cpu(i))
++ return i;
++
++ if (default_cpu == -1)
++ default_cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
++ cpu = default_cpu;
++
++ return cpu;
++}
++
++/*
++ * When add_timer_on() enqueues a timer into the timer wheel of an
++ * idle CPU then this timer might expire before the next timer event
++ * which is scheduled to wake up that CPU. In case of a completely
++ * idle system the next event might even be infinite time into the
++ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
++ * leaves the inner idle loop so the newly added timer is taken into
++ * account when the CPU goes back to idle and evaluates the timer
++ * wheel for the next timer event.
++ */
++static inline void wake_up_idle_cpu(int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++
++ if (cpu == smp_processor_id())
++ return;
++
++ if (set_nr_and_not_polling(rq->idle))
++ smp_send_reschedule(cpu);
++ else
++ trace_sched_wake_idle_without_ipi(cpu);
++}
++
++static inline bool wake_up_full_nohz_cpu(int cpu)
++{
++ /*
++ * We just need the target to call irq_exit() and re-evaluate
++ * the next tick. The nohz full kick at least implies that.
++ * If needed we can still optimize that later with an
++ * empty IRQ.
++ */
++ if (cpu_is_offline(cpu))
++ return true; /* Don't try to wake offline CPUs. */
++ if (tick_nohz_full_cpu(cpu)) {
++ if (cpu != smp_processor_id() ||
++ tick_nohz_tick_stopped())
++ tick_nohz_full_kick_cpu(cpu);
++ return true;
++ }
++
++ return false;
++}
++
++void wake_up_nohz_cpu(int cpu)
++{
++ if (!wake_up_full_nohz_cpu(cpu))
++ wake_up_idle_cpu(cpu);
++}
++
++static void nohz_csd_func(void *info)
++{
++ struct rq *rq = info;
++ int cpu = cpu_of(rq);
++ unsigned int flags;
++
++ /*
++ * Release the rq::nohz_csd.
++ */
++ flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(cpu));
++ WARN_ON(!(flags & NOHZ_KICK_MASK));
++
++ rq->idle_balance = idle_cpu(cpu);
++ if (rq->idle_balance && !need_resched()) {
++ rq->nohz_idle_balance = flags;
++ raise_softirq_irqoff(SCHED_SOFTIRQ);
++ }
++}
++
++#endif /* CONFIG_NO_HZ_COMMON */
++#endif /* CONFIG_SMP */
++
++static inline void check_preempt_curr(struct rq *rq)
++{
++ if (sched_rq_first_task(rq) != rq->curr)
++ resched_curr(rq);
++}
++
++#ifdef CONFIG_SCHED_HRTICK
++/*
++ * Use HR-timers to deliver accurate preemption points.
++ */
++
++static void hrtick_clear(struct rq *rq)
++{
++ if (hrtimer_active(&rq->hrtick_timer))
++ hrtimer_cancel(&rq->hrtick_timer);
++}
++
++/*
++ * High-resolution timer tick.
++ * Runs from hardirq context with interrupts disabled.
++ */
++static enum hrtimer_restart hrtick(struct hrtimer *timer)
++{
++ struct rq *rq = container_of(timer, struct rq, hrtick_timer);
++ struct task_struct *p;
++
++ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
++
++ raw_spin_lock(&rq->lock);
++ p = rq->curr;
++ p->time_slice = 0;
++ resched_curr(rq);
++ raw_spin_unlock(&rq->lock);
++
++ return HRTIMER_NORESTART;
++}
++
++/*
++ * Use hrtick when:
++ * - enabled by features
++ * - hrtimer is actually high res
++ */
++static inline int hrtick_enabled(struct rq *rq)
++{
++ /**
++ * Alt schedule FW doesn't support sched_feat yet
++ if (!sched_feat(HRTICK))
++ return 0;
++ */
++ if (!cpu_active(cpu_of(rq)))
++ return 0;
++ return hrtimer_is_hres_active(&rq->hrtick_timer);
++}
++
++#ifdef CONFIG_SMP
++
++static void __hrtick_restart(struct rq *rq)
++{
++ struct hrtimer *timer = &rq->hrtick_timer;
++ ktime_t time = rq->hrtick_time;
++
++ hrtimer_start(timer, time, HRTIMER_MODE_ABS_PINNED_HARD);
++}
++
++/*
++ * called from hardirq (IPI) context
++ */
++static void __hrtick_start(void *arg)
++{
++ struct rq *rq = arg;
++
++ raw_spin_lock(&rq->lock);
++ __hrtick_restart(rq);
++ raw_spin_unlock(&rq->lock);
++}
++
++/*
++ * Called to set the hrtick timer state.
++ *
++ * called with rq->lock held and irqs disabled
++ */
++void hrtick_start(struct rq *rq, u64 delay)
++{
++ struct hrtimer *timer = &rq->hrtick_timer;
++ s64 delta;
++
++ /*
++ * Don't schedule slices shorter than 10000ns, that just
++ * doesn't make sense and can cause timer DoS.
++ */
++ delta = max_t(s64, delay, 10000LL);
++
++ rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta);
++
++ if (rq == this_rq())
++ __hrtick_restart(rq);
++ else
++ smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd);
++}
++
++#else
++/*
++ * Called to set the hrtick timer state.
++ *
++ * called with rq->lock held and irqs disabled
++ */
++void hrtick_start(struct rq *rq, u64 delay)
++{
++ /*
++ * Don't schedule slices shorter than 10000ns, that just
++ * doesn't make sense. Rely on vruntime for fairness.
++ */
++ delay = max_t(u64, delay, 10000LL);
++ hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay),
++ HRTIMER_MODE_REL_PINNED_HARD);
++}
++#endif /* CONFIG_SMP */
++
++static void hrtick_rq_init(struct rq *rq)
++{
++#ifdef CONFIG_SMP
++ INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq);
++#endif
++
++ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
++ rq->hrtick_timer.function = hrtick;
++}
++#else /* CONFIG_SCHED_HRTICK */
++static inline int hrtick_enabled(struct rq *rq)
++{
++ return 0;
++}
++
++static inline void hrtick_clear(struct rq *rq)
++{
++}
++
++static inline void hrtick_rq_init(struct rq *rq)
++{
++}
++#endif /* CONFIG_SCHED_HRTICK */
++
++/*
++ * Calculate the current priority, i.e. the priority
++ * taken into account by the scheduler. This value might
++ * be boosted by RT tasks as it will be RT if the task got
++ * RT-boosted. If not then it returns p->normal_prio.
++ */
++static int effective_prio(struct task_struct *p)
++{
++ p->normal_prio = normal_prio(p);
++ /*
++ * If we are RT tasks or we were boosted to RT priority,
++ * keep the priority unchanged. Otherwise, update priority
++ * to the normal priority:
++ */
++ if (!rt_prio(p->prio))
++ return p->normal_prio;
++ return p->prio;
++}
++
++/*
++ * activate_task - move a task to the runqueue.
++ *
++ * Context: rq->lock
++ */
++static void activate_task(struct task_struct *p, struct rq *rq)
++{
++ enqueue_task(p, rq, ENQUEUE_WAKEUP);
++ p->on_rq = TASK_ON_RQ_QUEUED;
++
++ /*
++ * If in_iowait is set, the code below may not trigger any cpufreq
++ * utilization updates, so do it here explicitly with the IOWAIT flag
++ * passed.
++ */
++ cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT * p->in_iowait);
++}
++
++/*
++ * deactivate_task - remove a task from the runqueue.
++ *
++ * Context: rq->lock
++ */
++static inline void deactivate_task(struct task_struct *p, struct rq *rq)
++{
++ dequeue_task(p, rq, DEQUEUE_SLEEP);
++ p->on_rq = 0;
++ cpufreq_update_util(rq, 0);
++}
++
++static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
++{
++#ifdef CONFIG_SMP
++ /*
++ * After ->cpu is set up to a new value, task_access_lock(p, ...) can be
++ * successfully executed on another CPU. We must ensure that updates of
++ * per-task data have been completed by this moment.
++ */
++ smp_wmb();
++
++#ifdef CONFIG_THREAD_INFO_IN_TASK
++ WRITE_ONCE(p->cpu, cpu);
++#else
++ WRITE_ONCE(task_thread_info(p)->cpu, cpu);
++#endif
++#endif
++}
++
++static inline bool is_migration_disabled(struct task_struct *p)
++{
++#ifdef CONFIG_SMP
++ return p->migration_disabled;
++#else
++ return false;
++#endif
++}
++
++#define SCA_CHECK 0x01
++#define SCA_MIGRATE_DISABLE 0x02
++#define SCA_MIGRATE_ENABLE 0x04
++
++#ifdef CONFIG_SMP
++
++void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
++{
++#ifdef CONFIG_SCHED_DEBUG
++ /*
++ * We should never call set_task_cpu() on a blocked task,
++ * ttwu() will sort out the placement.
++ */
++ WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
++ !p->on_rq);
++#ifdef CONFIG_LOCKDEP
++ /*
++ * The caller should hold either p->pi_lock or rq->lock, when changing
++ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
++ *
++ * sched_move_task() holds both and thus holding either pins the cgroup,
++ * see task_group().
++ */
++ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
++ lockdep_is_held(&task_rq(p)->lock)));
++#endif
++ /*
++ * Clearly, migrating tasks to offline CPUs is a fairly daft thing.
++ */
++ WARN_ON_ONCE(!cpu_online(new_cpu));
++
++ WARN_ON_ONCE(is_migration_disabled(p));
++#endif
++ if (task_cpu(p) == new_cpu)
++ return;
++ trace_sched_migrate_task(p, new_cpu);
++ rseq_migrate(p);
++ perf_event_task_migrate(p);
++
++ __set_task_cpu(p, new_cpu);
++}
++
++static inline bool is_per_cpu_kthread(struct task_struct *p)
++{
++ return ((p->flags & PF_KTHREAD) && (1 == p->nr_cpus_allowed));
++}
++
++#define MDF_FORCE_ENABLED 0x80
++
++static void
++__do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask, u32 flags);
++
++static int __set_cpus_allowed_ptr(struct task_struct *p,
++ const struct cpumask *new_mask,
++ u32 flags);
++
++void migrate_disable(void)
++{
++ struct task_struct *p = current;
++
++ if (p->migration_disabled) {
++ p->migration_disabled++;
++ return;
++ }
++
++ preempt_disable();
++ this_rq()->nr_pinned++;
++ p->migration_disabled = 1;
++ p->migration_flags &= ~MDF_FORCE_ENABLED;
++
++ /*
++ * Violates locking rules! see comment in __do_set_cpus_allowed().
++ */
++ if (p->cpus_ptr == &p->cpus_mask)
++ __do_set_cpus_allowed(p, cpumask_of(smp_processor_id()), SCA_MIGRATE_DISABLE);
++
++ preempt_enable();
++}
++EXPORT_SYMBOL_GPL(migrate_disable);
++
++void migrate_enable(void)
++{
++ struct task_struct *p = current;
++
++ if (0 == p->migration_disabled)
++ return;
++
++ if (p->migration_disabled > 1) {
++ p->migration_disabled--;
++ return;
++ }
++
++ /*
++ * Ensure stop_task runs either before or after this, and that
++ * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule().
++ */
++ preempt_disable();
++ /*
++ * Assumption: current should be running on allowed cpu
++ */
++ WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &p->cpus_mask));
++ if (p->cpus_ptr != &p->cpus_mask)
++ __do_set_cpus_allowed(p, &p->cpus_mask, SCA_MIGRATE_ENABLE);
++ /*
++ * Mustn't clear migration_disabled() until cpus_ptr points back at the
++ * regular cpus_mask, otherwise things that race (eg.
++ * select_fallback_rq) get confused.
++ */
++ barrier();
++ p->migration_disabled = 0;
++ this_rq()->nr_pinned--;
++ preempt_enable();
++}
++EXPORT_SYMBOL_GPL(migrate_enable);
++
++static inline bool rq_has_pinned_tasks(struct rq *rq)
++{
++ return rq->nr_pinned;
++}
++
++/*
++ * Per-CPU kthreads are allowed to run on !active && online CPUs, see
++ * __set_cpus_allowed_ptr() and select_fallback_rq().
++ */
++static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
++{
++ /* When not in the task's cpumask, no point in looking further. */
++ if (!cpumask_test_cpu(cpu, p->cpus_ptr))
++ return false;
++
++ /* migrate_disabled() must be allowed to finish. */
++ if (is_migration_disabled(p))
++ return cpu_online(cpu);
++
++ /* Non kernel threads are not allowed during either online or offline. */
++ if (!(p->flags & PF_KTHREAD))
++ return cpu_active(cpu);
++
++ /* KTHREAD_IS_PER_CPU is always allowed. */
++ if (kthread_is_per_cpu(p))
++ return cpu_online(cpu);
++
++ /* Regular kernel threads don't get to stay during offline. */
++ if (cpu_rq(cpu)->balance_push)
++ return false;
++
++ /* But are allowed during online. */
++ return cpu_online(cpu);
++}
++
++/*
++ * This is how migration works:
++ *
++ * 1) we invoke migration_cpu_stop() on the target CPU using
++ * stop_one_cpu().
++ * 2) stopper starts to run (implicitly forcing the migrated thread
++ * off the CPU)
++ * 3) it checks whether the migrated task is still in the wrong runqueue.
++ * 4) if it's in the wrong runqueue then the migration thread removes
++ * it and puts it into the right queue.
++ * 5) stopper completes and stop_one_cpu() returns and the migration
++ * is done.
++ */
++
++/*
++ * move_queued_task - move a queued task to new rq.
++ *
++ * Returns (locked) new rq. Old rq's lock is released.
++ */
++static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int
++ new_cpu)
++{
++ lockdep_assert_held(&rq->lock);
++
++ WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING);
++ dequeue_task(p, rq, 0);
++ set_task_cpu(p, new_cpu);
++ raw_spin_unlock(&rq->lock);
++
++ rq = cpu_rq(new_cpu);
++
++ raw_spin_lock(&rq->lock);
++ BUG_ON(task_cpu(p) != new_cpu);
++ enqueue_task(p, rq, 0);
++ p->on_rq = TASK_ON_RQ_QUEUED;
++ check_preempt_curr(rq);
++
++ return rq;
++}
++
++struct migration_arg {
++ struct task_struct *task;
++ int dest_cpu;
++};
++
++/*
++ * Move (not current) task off this CPU, onto the destination CPU. We're doing
++ * this because either it can't run here any more (set_cpus_allowed()
++ * away from this CPU, or CPU going down), or because we're
++ * attempting to rebalance this task on exec (sched_exec).
++ *
++ * So we race with normal scheduler movements, but that's OK, as long
++ * as the task is no longer on this CPU.
++ */
++static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int
++ dest_cpu)
++{
++ /* Affinity changed (again). */
++ if (!is_cpu_allowed(p, dest_cpu))
++ return rq;
++
++ update_rq_clock(rq);
++ return move_queued_task(rq, p, dest_cpu);
++}
++
++/*
++ * migration_cpu_stop - this will be executed by a highprio stopper thread
++ * and performs thread migration by bumping thread off CPU then
++ * 'pushing' onto another runqueue.
++ */
++static int migration_cpu_stop(void *data)
++{
++ struct migration_arg *arg = data;
++ struct task_struct *p = arg->task;
++ struct rq *rq = this_rq();
++
++ /*
++ * The original target CPU might have gone down and we might
++ * be on another CPU but it doesn't matter.
++ */
++ local_irq_disable();
++ /*
++ * We need to explicitly wake pending tasks before running
++ * __migrate_task() such that we will not miss enforcing cpus_ptr
++ * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.
++ */
++ flush_smp_call_function_from_idle();
++
++ raw_spin_lock(&p->pi_lock);
++ raw_spin_lock(&rq->lock);
++ /*
++ * If task_rq(p) != rq, it cannot be migrated here, because we're
++ * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because
++ * we're holding p->pi_lock.
++ */
++ if (task_rq(p) == rq && task_on_rq_queued(p))
++ rq = __migrate_task(rq, p, arg->dest_cpu);
++ raw_spin_unlock(&rq->lock);
++ raw_spin_unlock(&p->pi_lock);
++
++ local_irq_enable();
++ return 0;
++}
++
++static inline void
++set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask, u32 flags)
++{
++ if (flags & (SCA_MIGRATE_ENABLE | SCA_MIGRATE_DISABLE)) {
++ p->cpus_ptr = new_mask;
++ return;
++ }
++
++ cpumask_copy(&p->cpus_mask, new_mask);
++ p->nr_cpus_allowed = cpumask_weight(new_mask);
++}
++
++static void
++__do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask, u32 flags)
++{
++ /*
++ * This here violates the locking rules for affinity, since we're only
++ * supposed to change these variables while holding both rq->lock and
++ * p->pi_lock.
++ *
++ * HOWEVER, it magically works, because ttwu() is the only code that
++ * accesses these variables under p->pi_lock and only does so after
++ * smp_cond_load_acquire(&p->on_cpu, !VAL), and we're in __schedule()
++ * before finish_task().
++ *
++ * XXX do further audits, this smells like something putrid.
++ */
++ if (flags & (SCA_MIGRATE_DISABLE | SCA_MIGRATE_ENABLE))
++ SCHED_WARN_ON(!p->on_cpu);
++ else
++ lockdep_assert_held(&p->pi_lock);
++
++ set_cpus_allowed_common(p, new_mask, flags);
++}
++
++void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
++{
++ __do_set_cpus_allowed(p, new_mask, 0);
++}
++
++#endif
++
++/**
++ * task_curr - is this task currently executing on a CPU?
++ * @p: the task in question.
++ *
++ * Return: 1 if the task is currently executing. 0 otherwise.
++ */
++inline int task_curr(const struct task_struct *p)
++{
++ return cpu_curr(task_cpu(p)) == p;
++}
++
++#ifdef CONFIG_SMP
++/*
++ * wait_task_inactive - wait for a thread to unschedule.
++ *
++ * If @match_state is nonzero, it's the @p->state value just checked and
++ * not expected to change. If it changes, i.e. @p might have woken up,
++ * then return zero. When we succeed in waiting for @p to be off its CPU,
++ * we return a positive number (its total switch count). If a second call
++ * a short while later returns the same number, the caller can be sure that
++ * @p has remained unscheduled the whole time.
++ *
++ * The caller must ensure that the task *will* unschedule sometime soon,
++ * else this function might spin for a *long* time. This function can't
++ * be called with interrupts off, or it may introduce deadlock with
++ * smp_call_function() if an IPI is sent by the same process we are
++ * waiting to become inactive.
++ */
++unsigned long wait_task_inactive(struct task_struct *p, long match_state)
++{
++ unsigned long flags;
++ bool running, on_rq;
++ unsigned long ncsw;
++ struct rq *rq;
++ raw_spinlock_t *lock;
++
++ for (;;) {
++ rq = task_rq(p);
++
++ /*
++ * If the task is actively running on another CPU
++ * still, just relax and busy-wait without holding
++ * any locks.
++ *
++ * NOTE! Since we don't hold any locks, it's not
++ * even sure that "rq" stays as the right runqueue!
++ * But we don't care, since this will return false
++ * if the runqueue has changed and p is actually now
++ * running somewhere else!
++ */
++ while (task_running(p) && p == rq->curr) {
++ if (match_state && unlikely(p->state != match_state))
++ return 0;
++ cpu_relax();
++ }
++
++ /*
++ * Ok, time to look more closely! We need the rq
++ * lock now, to be *sure*. If we're wrong, we'll
++ * just go back and repeat.
++ */
++ task_access_lock_irqsave(p, &lock, &flags);
++ trace_sched_wait_task(p);
++ running = task_running(p);
++ on_rq = p->on_rq;
++ ncsw = 0;
++ if (!match_state || p->state == match_state)
++ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
++ task_access_unlock_irqrestore(p, lock, &flags);
++
++ /*
++ * If it changed from the expected state, bail out now.
++ */
++ if (unlikely(!ncsw))
++ break;
++
++ /*
++ * Was it really running after all now that we
++ * checked with the proper locks actually held?
++ *
++ * Oops. Go back and try again..
++ */
++ if (unlikely(running)) {
++ cpu_relax();
++ continue;
++ }
++
++ /*
++ * It's not enough that it's not actively running,
++ * it must be off the runqueue _entirely_, and not
++ * preempted!
++ *
++ * So if it was still runnable (but just not actively
++ * running right now), it's preempted, and we should
++ * yield - it could be a while.
++ */
++ if (unlikely(on_rq)) {
++ ktime_t to = NSEC_PER_SEC / HZ;
++
++ set_current_state(TASK_UNINTERRUPTIBLE);
++ schedule_hrtimeout(&to, HRTIMER_MODE_REL);
++ continue;
++ }
++
++ /*
++ * Ahh, all good. It wasn't running, and it wasn't
++ * runnable, which means that it will never become
++ * running in the future either. We're all done!
++ */
++ break;
++ }
++
++ return ncsw;
++}
++
++/***
++ * kick_process - kick a running thread to enter/exit the kernel
++ * @p: the to-be-kicked thread
++ *
++ * Cause a process which is running on another CPU to enter
++ * kernel-mode, without any delay. (to get signals handled.)
++ *
++ * NOTE: this function doesn't have to take the runqueue lock,
++ * because all it wants to ensure is that the remote task enters
++ * the kernel. If the IPI races and the task has been migrated
++ * to another CPU then no harm is done and the purpose has been
++ * achieved as well.
++ */
++void kick_process(struct task_struct *p)
++{
++ int cpu;
++
++ preempt_disable();
++ cpu = task_cpu(p);
++ if ((cpu != smp_processor_id()) && task_curr(p))
++ smp_send_reschedule(cpu);
++ preempt_enable();
++}
++EXPORT_SYMBOL_GPL(kick_process);
++
++/*
++ * ->cpus_ptr is protected by both rq->lock and p->pi_lock
++ *
++ * A few notes on cpu_active vs cpu_online:
++ *
++ * - cpu_active must be a subset of cpu_online
++ *
++ * - on CPU-up we allow per-CPU kthreads on the online && !active CPU,
++ * see __set_cpus_allowed_ptr(). At this point the newly online
++ * CPU isn't yet part of the sched domains, and balancing will not
++ * see it.
++ *
++ * - on cpu-down we clear cpu_active() to mask the sched domains and
++ * avoid the load balancer to place new tasks on the to be removed
++ * CPU. Existing tasks will remain running there and will be taken
++ * off.
++ *
++ * This means that fallback selection must not select !active CPUs.
++ * And can assume that any active CPU must be online. Conversely
++ * select_task_rq() below may allow selection of !active CPUs in order
++ * to satisfy the above rules.
++ */
++static int select_fallback_rq(int cpu, struct task_struct *p)
++{
++ int nid = cpu_to_node(cpu);
++ const struct cpumask *nodemask = NULL;
++ enum { cpuset, possible, fail } state = cpuset;
++ int dest_cpu;
++
++ /*
++ * If the node that the CPU is on has been offlined, cpu_to_node()
++ * will return -1. There is no CPU on the node, and we should
++ * select the CPU on the other node.
++ */
++ if (nid != -1) {
++ nodemask = cpumask_of_node(nid);
++
++ /* Look for allowed, online CPU in same node. */
++ for_each_cpu(dest_cpu, nodemask) {
++ if (!cpu_active(dest_cpu))
++ continue;
++ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr))
++ return dest_cpu;
++ }
++ }
++
++ for (;;) {
++ /* Any allowed, online CPU? */
++ for_each_cpu(dest_cpu, p->cpus_ptr) {
++ if (!is_cpu_allowed(p, dest_cpu))
++ continue;
++ goto out;
++ }
++
++ /* No more Mr. Nice Guy. */
++ switch (state) {
++ case cpuset:
++ if (IS_ENABLED(CONFIG_CPUSETS)) {
++ cpuset_cpus_allowed_fallback(p);
++ state = possible;
++ break;
++ }
++ fallthrough;
++ case possible:
++ /*
++ * XXX When called from select_task_rq() we only
++ * hold p->pi_lock and again violate locking order.
++ *
++ * More yuck to audit.
++ */
++ do_set_cpus_allowed(p, cpu_possible_mask);
++ state = fail;
++ break;
++
++ case fail:
++ BUG();
++ break;
++ }
++ }
++
++out:
++ if (state != cpuset) {
++ /*
++ * Don't tell them about moving exiting tasks or
++ * kernel threads (both mm NULL), since they never
++ * leave kernel.
++ */
++ if (p->mm && printk_ratelimit()) {
++ printk_deferred("process %d (%s) no longer affine to cpu%d\n",
++ task_pid_nr(p), p->comm, cpu);
++ }
++ }
++
++ return dest_cpu;
++}
++
++static inline int select_task_rq(struct task_struct *p, struct rq *rq)
++{
++ cpumask_t chk_mask, tmp;
++
++ if (unlikely(!cpumask_and(&chk_mask, p->cpus_ptr, cpu_online_mask)))
++ return select_fallback_rq(task_cpu(p), p);
++
++ if (
++#ifdef CONFIG_SCHED_SMT
++ cpumask_and(&tmp, &chk_mask, &sched_sg_idle_mask) ||
++#endif
++ cpumask_and(&tmp, &chk_mask, &sched_rq_watermark[IDLE_WM]) ||
++ cpumask_and(&tmp, &chk_mask,
++ &sched_rq_watermark[task_sched_prio(p, rq) + 1]))
++ return best_mask_cpu(task_cpu(p), &tmp);
++
++ return best_mask_cpu(task_cpu(p), &chk_mask);
++}
++
++void sched_set_stop_task(int cpu, struct task_struct *stop)
++{
++ static struct lock_class_key stop_pi_lock;
++ struct sched_param stop_param = { .sched_priority = STOP_PRIO };
++ struct sched_param start_param = { .sched_priority = 0 };
++ struct task_struct *old_stop = cpu_rq(cpu)->stop;
++
++ if (stop) {
++ /*
++ * Make it appear like a SCHED_FIFO task, its something
++ * userspace knows about and won't get confused about.
++ *
++ * Also, it will make PI more or less work without too
++ * much confusion -- but then, stop work should not
++ * rely on PI working anyway.
++ */
++ sched_setscheduler_nocheck(stop, SCHED_FIFO, &stop_param);
++
++ /*
++ * The PI code calls rt_mutex_setprio() with ->pi_lock held to
++ * adjust the effective priority of a task. As a result,
++ * rt_mutex_setprio() can trigger (RT) balancing operations,
++ * which can then trigger wakeups of the stop thread to push
++ * around the current task.
++ *
++ * The stop task itself will never be part of the PI-chain, it
++ * never blocks, therefore that ->pi_lock recursion is safe.
++ * Tell lockdep about this by placing the stop->pi_lock in its
++ * own class.
++ */
++ lockdep_set_class(&stop->pi_lock, &stop_pi_lock);
++ }
++
++ cpu_rq(cpu)->stop = stop;
++
++ if (old_stop) {
++ /*
++ * Reset it back to a normal scheduling policy so that
++ * it can die in pieces.
++ */
++ sched_setscheduler_nocheck(old_stop, SCHED_NORMAL, &start_param);
++ }
++}
++
++/*
++ * Change a given task's CPU affinity. Migrate the thread to a
++ * proper CPU and schedule it away if the CPU it's executing on
++ * is removed from the allowed bitmask.
++ *
++ * NOTE: the caller must have a valid reference to the task, the
++ * task must not exit() & deallocate itself prematurely. The
++ * call is not atomic; no spinlocks may be held.
++ */
++static int __set_cpus_allowed_ptr(struct task_struct *p,
++ const struct cpumask *new_mask,
++ u32 flags)
++{
++ const struct cpumask *cpu_valid_mask = cpu_active_mask;
++ int dest_cpu;
++ unsigned long irq_flags;
++ struct rq *rq;
++ raw_spinlock_t *lock;
++ int ret = 0;
++
++ raw_spin_lock_irqsave(&p->pi_lock, irq_flags);
++ rq = __task_access_lock(p, &lock);
++
++ if (p->flags & PF_KTHREAD || is_migration_disabled(p)) {
++ /*
++ * Kernel threads are allowed on online && !active CPUs,
++ * however, during cpu-hot-unplug, even these might get pushed
++ * away if not KTHREAD_IS_PER_CPU.
++ *
++ * Specifically, migration_disabled() tasks must not fail the
++ * cpumask_any_and_distribute() pick below, esp. so on
++ * SCA_MIGRATE_ENABLE, otherwise we'll not call
++ * set_cpus_allowed_common() and actually reset p->cpus_ptr.
++ */
++ cpu_valid_mask = cpu_online_mask;
++ }
++
++ /*
++ * Must re-check here, to close a race against __kthread_bind(),
++ * sched_setaffinity() is not guaranteed to observe the flag.
++ */
++ if ((flags & SCA_CHECK) && (p->flags & PF_NO_SETAFFINITY)) {
++ ret = -EINVAL;
++ goto out;
++ }
++
++ if (cpumask_equal(&p->cpus_mask, new_mask))
++ goto out;
++
++ dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);
++ if (dest_cpu >= nr_cpu_ids) {
++ ret = -EINVAL;
++ goto out;
++ }
++
++ __do_set_cpus_allowed(p, new_mask, flags);
++
++ /* Can the task run on the task's current CPU? If so, we're done */
++ if (cpumask_test_cpu(task_cpu(p), new_mask))
++ goto out;
++
++ if (p->migration_disabled) {
++ if (p->cpus_ptr != &p->cpus_mask)
++ __do_set_cpus_allowed(p, &p->cpus_mask, SCA_MIGRATE_ENABLE);
++ p->migration_disabled = 0;
++ p->migration_flags |= MDF_FORCE_ENABLED;
++ /* When p is migrate_disabled, rq->lock should be held */
++ rq->nr_pinned--;
++ }
++
++ if (task_running(p) || p->state == TASK_WAKING) {
++ struct migration_arg arg = { p, dest_cpu };
++
++ /* Need help from migration thread: drop lock and wait. */
++ __task_access_unlock(p, lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags);
++ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
++ return 0;
++ }
++ if (task_on_rq_queued(p)) {
++ /*
++ * OK, since we're going to drop the lock immediately
++ * afterwards anyway.
++ */
++ update_rq_clock(rq);
++ rq = move_queued_task(rq, p, dest_cpu);
++ lock = &rq->lock;
++ }
++
++out:
++ __task_access_unlock(p, lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags);
++
++ return ret;
++}
++
++int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
++{
++ return __set_cpus_allowed_ptr(p, new_mask, 0);
++}
++EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
++
++#else /* CONFIG_SMP */
++
++static inline int select_task_rq(struct task_struct *p, struct rq *rq)
++{
++ return 0;
++}
++
++static inline int
++__set_cpus_allowed_ptr(struct task_struct *p,
++ const struct cpumask *new_mask,
++ u32 flags)
++{
++ return set_cpus_allowed_ptr(p, new_mask);
++}
++
++static inline bool rq_has_pinned_tasks(struct rq *rq)
++{
++ return false;
++}
++
++#endif /* !CONFIG_SMP */
++
++static void
++ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
++{
++ struct rq *rq;
++
++ if (!schedstat_enabled())
++ return;
++
++ rq = this_rq();
++
++#ifdef CONFIG_SMP
++ if (cpu == rq->cpu)
++ __schedstat_inc(rq->ttwu_local);
++ else {
++ /** Alt schedule FW ToDo:
++ * How to do ttwu_wake_remote
++ */
++ }
++#endif /* CONFIG_SMP */
++
++ __schedstat_inc(rq->ttwu_count);
++}
++
++/*
++ * Mark the task runnable and perform wakeup-preemption.
++ */
++static inline void
++ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
++{
++ check_preempt_curr(rq);
++ p->state = TASK_RUNNING;
++ trace_sched_wakeup(p);
++}
++
++static inline void
++ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags)
++{
++ if (p->sched_contributes_to_load)
++ rq->nr_uninterruptible--;
++
++ if (
++#ifdef CONFIG_SMP
++ !(wake_flags & WF_MIGRATED) &&
++#endif
++ p->in_iowait) {
++ delayacct_blkio_end(p);
++ atomic_dec(&task_rq(p)->nr_iowait);
++ }
++
++ activate_task(p, rq);
++ ttwu_do_wakeup(rq, p, 0);
++}
++
++/*
++ * Consider @p being inside a wait loop:
++ *
++ * for (;;) {
++ * set_current_state(TASK_UNINTERRUPTIBLE);
++ *
++ * if (CONDITION)
++ * break;
++ *
++ * schedule();
++ * }
++ * __set_current_state(TASK_RUNNING);
++ *
++ * between set_current_state() and schedule(). In this case @p is still
++ * runnable, so all that needs doing is change p->state back to TASK_RUNNING in
++ * an atomic manner.
++ *
++ * By taking task_rq(p)->lock we serialize against schedule(), if @p->on_rq
++ * then schedule() must still happen and p->state can be changed to
++ * TASK_RUNNING. Otherwise we lost the race, schedule() has happened, and we
++ * need to do a full wakeup with enqueue.
++ *
++ * Returns: %true when the wakeup is done,
++ * %false otherwise.
++ */
++static int ttwu_runnable(struct task_struct *p, int wake_flags)
++{
++ struct rq *rq;
++ raw_spinlock_t *lock;
++ int ret = 0;
++
++ rq = __task_access_lock(p, &lock);
++ if (task_on_rq_queued(p)) {
++ /* check_preempt_curr() may use rq clock */
++ update_rq_clock(rq);
++ ttwu_do_wakeup(rq, p, wake_flags);
++ ret = 1;
++ }
++ __task_access_unlock(p, lock);
++
++ return ret;
++}
++
++#ifdef CONFIG_SMP
++void sched_ttwu_pending(void *arg)
++{
++ struct llist_node *llist = arg;
++ struct rq *rq = this_rq();
++ struct task_struct *p, *t;
++ struct rq_flags rf;
++
++ if (!llist)
++ return;
++
++ /*
++ * rq::ttwu_pending racy indication of out-standing wakeups.
++ * Races such that false-negatives are possible, since they
++ * are shorter lived that false-positives would be.
++ */
++ WRITE_ONCE(rq->ttwu_pending, 0);
++
++ rq_lock_irqsave(rq, &rf);
++ update_rq_clock(rq);
++
++ llist_for_each_entry_safe(p, t, llist, wake_entry.llist) {
++ if (WARN_ON_ONCE(p->on_cpu))
++ smp_cond_load_acquire(&p->on_cpu, !VAL);
++
++ if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq)))
++ set_task_cpu(p, cpu_of(rq));
++
++ ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0);
++ }
++
++ rq_unlock_irqrestore(rq, &rf);
++}
++
++void send_call_function_single_ipi(int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++
++ if (!set_nr_if_polling(rq->idle))
++ arch_send_call_function_single_ipi(cpu);
++ else
++ trace_sched_wake_idle_without_ipi(cpu);
++}
++
++/*
++ * Queue a task on the target CPUs wake_list and wake the CPU via IPI if
++ * necessary. The wakee CPU on receipt of the IPI will queue the task
++ * via sched_ttwu_wakeup() for activation so the wakee incurs the cost
++ * of the wakeup instead of the waker.
++ */
++static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
++{
++ struct rq *rq = cpu_rq(cpu);
++
++ p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED);
++
++ WRITE_ONCE(rq->ttwu_pending, 1);
++ __smp_call_single_queue(cpu, &p->wake_entry.llist);
++}
++
++static inline bool ttwu_queue_cond(int cpu, int wake_flags)
++{
++ /*
++ * Do not complicate things with the async wake_list while the CPU is
++ * in hotplug state.
++ */
++ if (!cpu_active(cpu))
++ return false;
++
++ /*
++ * If the CPU does not share cache, then queue the task on the
++ * remote rqs wakelist to avoid accessing remote data.
++ */
++ if (!cpus_share_cache(smp_processor_id(), cpu))
++ return true;
++
++ /*
++ * If the task is descheduling and the only running task on the
++ * CPU then use the wakelist to offload the task activation to
++ * the soon-to-be-idle CPU as the current CPU is likely busy.
++ * nr_running is checked to avoid unnecessary task stacking.
++ */
++ if ((wake_flags & WF_ON_CPU) && cpu_rq(cpu)->nr_running <= 1)
++ return true;
++
++ return false;
++}
++
++static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
++{
++ if (__is_defined(ALT_SCHED_TTWU_QUEUE) && ttwu_queue_cond(cpu, wake_flags)) {
++ if (WARN_ON_ONCE(cpu == smp_processor_id()))
++ return false;
++
++ sched_clock_cpu(cpu); /* Sync clocks across CPUs */
++ __ttwu_queue_wakelist(p, cpu, wake_flags);
++ return true;
++ }
++
++ return false;
++}
++
++void wake_up_if_idle(int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++ unsigned long flags;
++
++ rcu_read_lock();
++
++ if (!is_idle_task(rcu_dereference(rq->curr)))
++ goto out;
++
++ if (set_nr_if_polling(rq->idle)) {
++ trace_sched_wake_idle_without_ipi(cpu);
++ } else {
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ if (is_idle_task(rq->curr))
++ smp_send_reschedule(cpu);
++ /* Else CPU is not idle, do nothing here */
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++ }
++
++out:
++ rcu_read_unlock();
++}
++
++bool cpus_share_cache(int this_cpu, int that_cpu)
++{
++ return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);
++}
++#else /* !CONFIG_SMP */
++
++static inline bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
++{
++ return false;
++}
++
++#endif /* CONFIG_SMP */
++
++static inline void ttwu_queue(struct task_struct *p, int cpu, int wake_flags)
++{
++ struct rq *rq = cpu_rq(cpu);
++
++ if (ttwu_queue_wakelist(p, cpu, wake_flags))
++ return;
++
++ raw_spin_lock(&rq->lock);
++ update_rq_clock(rq);
++ ttwu_do_activate(rq, p, wake_flags);
++ raw_spin_unlock(&rq->lock);
++}
++
++/*
++ * Notes on Program-Order guarantees on SMP systems.
++ *
++ * MIGRATION
++ *
++ * The basic program-order guarantee on SMP systems is that when a task [t]
++ * migrates, all its activity on its old CPU [c0] happens-before any subsequent
++ * execution on its new CPU [c1].
++ *
++ * For migration (of runnable tasks) this is provided by the following means:
++ *
++ * A) UNLOCK of the rq(c0)->lock scheduling out task t
++ * B) migration for t is required to synchronize *both* rq(c0)->lock and
++ * rq(c1)->lock (if not at the same time, then in that order).
++ * C) LOCK of the rq(c1)->lock scheduling in task
++ *
++ * Transitivity guarantees that B happens after A and C after B.
++ * Note: we only require RCpc transitivity.
++ * Note: the CPU doing B need not be c0 or c1
++ *
++ * Example:
++ *
++ * CPU0 CPU1 CPU2
++ *
++ * LOCK rq(0)->lock
++ * sched-out X
++ * sched-in Y
++ * UNLOCK rq(0)->lock
++ *
++ * LOCK rq(0)->lock // orders against CPU0
++ * dequeue X
++ * UNLOCK rq(0)->lock
++ *
++ * LOCK rq(1)->lock
++ * enqueue X
++ * UNLOCK rq(1)->lock
++ *
++ * LOCK rq(1)->lock // orders against CPU2
++ * sched-out Z
++ * sched-in X
++ * UNLOCK rq(1)->lock
++ *
++ *
++ * BLOCKING -- aka. SLEEP + WAKEUP
++ *
++ * For blocking we (obviously) need to provide the same guarantee as for
++ * migration. However the means are completely different as there is no lock
++ * chain to provide order. Instead we do:
++ *
++ * 1) smp_store_release(X->on_cpu, 0) -- finish_task()
++ * 2) smp_cond_load_acquire(!X->on_cpu) -- try_to_wake_up()
++ *
++ * Example:
++ *
++ * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule)
++ *
++ * LOCK rq(0)->lock LOCK X->pi_lock
++ * dequeue X
++ * sched-out X
++ * smp_store_release(X->on_cpu, 0);
++ *
++ * smp_cond_load_acquire(&X->on_cpu, !VAL);
++ * X->state = WAKING
++ * set_task_cpu(X,2)
++ *
++ * LOCK rq(2)->lock
++ * enqueue X
++ * X->state = RUNNING
++ * UNLOCK rq(2)->lock
++ *
++ * LOCK rq(2)->lock // orders against CPU1
++ * sched-out Z
++ * sched-in X
++ * UNLOCK rq(2)->lock
++ *
++ * UNLOCK X->pi_lock
++ * UNLOCK rq(0)->lock
++ *
++ *
++ * However; for wakeups there is a second guarantee we must provide, namely we
++ * must observe the state that lead to our wakeup. That is, not only must our
++ * task observe its own prior state, it must also observe the stores prior to
++ * its wakeup.
++ *
++ * This means that any means of doing remote wakeups must order the CPU doing
++ * the wakeup against the CPU the task is going to end up running on. This,
++ * however, is already required for the regular Program-Order guarantee above,
++ * since the waking CPU is the one issueing the ACQUIRE (smp_cond_load_acquire).
++ *
++ */
++
++/**
++ * try_to_wake_up - wake up a thread
++ * @p: the thread to be awakened
++ * @state: the mask of task states that can be woken
++ * @wake_flags: wake modifier flags (WF_*)
++ *
++ * Conceptually does:
++ *
++ * If (@state & @p->state) @p->state = TASK_RUNNING.
++ *
++ * If the task was not queued/runnable, also place it back on a runqueue.
++ *
++ * This function is atomic against schedule() which would dequeue the task.
++ *
++ * It issues a full memory barrier before accessing @p->state, see the comment
++ * with set_current_state().
++ *
++ * Uses p->pi_lock to serialize against concurrent wake-ups.
++ *
++ * Relies on p->pi_lock stabilizing:
++ * - p->sched_class
++ * - p->cpus_ptr
++ * - p->sched_task_group
++ * in order to do migration, see its use of select_task_rq()/set_task_cpu().
++ *
++ * Tries really hard to only take one task_rq(p)->lock for performance.
++ * Takes rq->lock in:
++ * - ttwu_runnable() -- old rq, unavoidable, see comment there;
++ * - ttwu_queue() -- new rq, for enqueue of the task;
++ * - psi_ttwu_dequeue() -- much sadness :-( accounting will kill us.
++ *
++ * As a consequence we race really badly with just about everything. See the
++ * many memory barriers and their comments for details.
++ *
++ * Return: %true if @p->state changes (an actual wakeup was done),
++ * %false otherwise.
++ */
++static int try_to_wake_up(struct task_struct *p, unsigned int state,
++ int wake_flags)
++{
++ unsigned long flags;
++ int cpu, success = 0;
++
++ preempt_disable();
++ if (p == current) {
++ /*
++ * We're waking current, this means 'p->on_rq' and 'task_cpu(p)
++ * == smp_processor_id()'. Together this means we can special
++ * case the whole 'p->on_rq && ttwu_runnable()' case below
++ * without taking any locks.
++ *
++ * In particular:
++ * - we rely on Program-Order guarantees for all the ordering,
++ * - we're serialized against set_special_state() by virtue of
++ * it disabling IRQs (this allows not taking ->pi_lock).
++ */
++ if (!(p->state & state))
++ goto out;
++
++ success = 1;
++ trace_sched_waking(p);
++ p->state = TASK_RUNNING;
++ trace_sched_wakeup(p);
++ goto out;
++ }
++
++ /*
++ * If we are going to wake up a thread waiting for CONDITION we
++ * need to ensure that CONDITION=1 done by the caller can not be
++ * reordered with p->state check below. This pairs with smp_store_mb()
++ * in set_current_state() that the waiting thread does.
++ */
++ raw_spin_lock_irqsave(&p->pi_lock, flags);
++ smp_mb__after_spinlock();
++ if (!(p->state & state))
++ goto unlock;
++
++ trace_sched_waking(p);
++
++ /* We're going to change ->state: */
++ success = 1;
++
++ /*
++ * Ensure we load p->on_rq _after_ p->state, otherwise it would
++ * be possible to, falsely, observe p->on_rq == 0 and get stuck
++ * in smp_cond_load_acquire() below.
++ *
++ * sched_ttwu_pending() try_to_wake_up()
++ * STORE p->on_rq = 1 LOAD p->state
++ * UNLOCK rq->lock
++ *
++ * __schedule() (switch to task 'p')
++ * LOCK rq->lock smp_rmb();
++ * smp_mb__after_spinlock();
++ * UNLOCK rq->lock
++ *
++ * [task p]
++ * STORE p->state = UNINTERRUPTIBLE LOAD p->on_rq
++ *
++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in
++ * __schedule(). See the comment for smp_mb__after_spinlock().
++ *
++ * A similar smb_rmb() lives in try_invoke_on_locked_down_task().
++ */
++ smp_rmb();
++ if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags))
++ goto unlock;
++
++#ifdef CONFIG_SMP
++ /*
++ * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be
++ * possible to, falsely, observe p->on_cpu == 0.
++ *
++ * One must be running (->on_cpu == 1) in order to remove oneself
++ * from the runqueue.
++ *
++ * __schedule() (switch to task 'p') try_to_wake_up()
++ * STORE p->on_cpu = 1 LOAD p->on_rq
++ * UNLOCK rq->lock
++ *
++ * __schedule() (put 'p' to sleep)
++ * LOCK rq->lock smp_rmb();
++ * smp_mb__after_spinlock();
++ * STORE p->on_rq = 0 LOAD p->on_cpu
++ *
++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in
++ * __schedule(). See the comment for smp_mb__after_spinlock().
++ *
++ * Form a control-dep-acquire with p->on_rq == 0 above, to ensure
++ * schedule()'s deactivate_task() has 'happened' and p will no longer
++ * care about it's own p->state. See the comment in __schedule().
++ */
++ smp_acquire__after_ctrl_dep();
++
++ /*
++ * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq
++ * == 0), which means we need to do an enqueue, change p->state to
++ * TASK_WAKING such that we can unlock p->pi_lock before doing the
++ * enqueue, such as ttwu_queue_wakelist().
++ */
++ p->state = TASK_WAKING;
++
++ /*
++ * If the owning (remote) CPU is still in the middle of schedule() with
++ * this task as prev, considering queueing p on the remote CPUs wake_list
++ * which potentially sends an IPI instead of spinning on p->on_cpu to
++ * let the waker make forward progress. This is safe because IRQs are
++ * disabled and the IPI will deliver after on_cpu is cleared.
++ *
++ * Ensure we load task_cpu(p) after p->on_cpu:
++ *
++ * set_task_cpu(p, cpu);
++ * STORE p->cpu = @cpu
++ * __schedule() (switch to task 'p')
++ * LOCK rq->lock
++ * smp_mb__after_spin_lock() smp_cond_load_acquire(&p->on_cpu)
++ * STORE p->on_cpu = 1 LOAD p->cpu
++ *
++ * to ensure we observe the correct CPU on which the task is currently
++ * scheduling.
++ */
++ if (smp_load_acquire(&p->on_cpu) &&
++ ttwu_queue_wakelist(p, task_cpu(p), wake_flags | WF_ON_CPU))
++ goto unlock;
++
++ /*
++ * If the owning (remote) CPU is still in the middle of schedule() with
++ * this task as prev, wait until it's done referencing the task.
++ *
++ * Pairs with the smp_store_release() in finish_task().
++ *
++ * This ensures that tasks getting woken will be fully ordered against
++ * their previous state and preserve Program Order.
++ */
++ smp_cond_load_acquire(&p->on_cpu, !VAL);
++
++ sched_task_ttwu(p);
++
++ cpu = select_task_rq(p, this_rq());
++
++ if (cpu != task_cpu(p)) {
++ if (p->in_iowait) {
++ delayacct_blkio_end(p);
++ atomic_dec(&task_rq(p)->nr_iowait);
++ }
++
++ wake_flags |= WF_MIGRATED;
++ psi_ttwu_dequeue(p);
++ set_task_cpu(p, cpu);
++ }
++#else
++ cpu = task_cpu(p);
++#endif /* CONFIG_SMP */
++
++ ttwu_queue(p, cpu, wake_flags);
++unlock:
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++out:
++ if (success)
++ ttwu_stat(p, task_cpu(p), wake_flags);
++ preempt_enable();
++
++ return success;
++}
++
++/**
++ * try_invoke_on_locked_down_task - Invoke a function on task in fixed state
++ * @p: Process for which the function is to be invoked, can be @current.
++ * @func: Function to invoke.
++ * @arg: Argument to function.
++ *
++ * If the specified task can be quickly locked into a definite state
++ * (either sleeping or on a given runqueue), arrange to keep it in that
++ * state while invoking @func(@arg). This function can use ->on_rq and
++ * task_curr() to work out what the state is, if required. Given that
++ * @func can be invoked with a runqueue lock held, it had better be quite
++ * lightweight.
++ *
++ * Returns:
++ * @false if the task slipped out from under the locks.
++ * @true if the task was locked onto a runqueue or is sleeping.
++ * However, @func can override this by returning @false.
++ */
++bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg)
++{
++ struct rq_flags rf;
++ bool ret = false;
++ struct rq *rq;
++
++ raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
++ if (p->on_rq) {
++ rq = __task_rq_lock(p, &rf);
++ if (task_rq(p) == rq)
++ ret = func(p, arg);
++ __task_rq_unlock(rq, &rf);
++ } else {
++ switch (p->state) {
++ case TASK_RUNNING:
++ case TASK_WAKING:
++ break;
++ default:
++ smp_rmb(); // See smp_rmb() comment in try_to_wake_up().
++ if (!p->on_rq)
++ ret = func(p, arg);
++ }
++ }
++ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags);
++ return ret;
++}
++
++/**
++ * wake_up_process - Wake up a specific process
++ * @p: The process to be woken up.
++ *
++ * Attempt to wake up the nominated process and move it to the set of runnable
++ * processes.
++ *
++ * Return: 1 if the process was woken up, 0 if it was already running.
++ *
++ * This function executes a full memory barrier before accessing the task state.
++ */
++int wake_up_process(struct task_struct *p)
++{
++ return try_to_wake_up(p, TASK_NORMAL, 0);
++}
++EXPORT_SYMBOL(wake_up_process);
++
++int wake_up_state(struct task_struct *p, unsigned int state)
++{
++ return try_to_wake_up(p, state, 0);
++}
++
++/*
++ * Perform scheduler related setup for a newly forked process p.
++ * p is forked by current.
++ *
++ * __sched_fork() is basic setup used by init_idle() too:
++ */
++static inline void __sched_fork(unsigned long clone_flags, struct task_struct *p)
++{
++ p->on_rq = 0;
++ p->on_cpu = 0;
++ p->utime = 0;
++ p->stime = 0;
++ p->sched_time = 0;
++
++#ifdef CONFIG_PREEMPT_NOTIFIERS
++ INIT_HLIST_HEAD(&p->preempt_notifiers);
++#endif
++
++#ifdef CONFIG_COMPACTION
++ p->capture_control = NULL;
++#endif
++#ifdef CONFIG_SMP
++ p->wake_entry.u_flags = CSD_TYPE_TTWU;
++#endif
++}
++
++/*
++ * fork()/clone()-time setup:
++ */
++int sched_fork(unsigned long clone_flags, struct task_struct *p)
++{
++ unsigned long flags;
++ struct rq *rq;
++
++ __sched_fork(clone_flags, p);
++ /*
++ * We mark the process as NEW here. This guarantees that
++ * nobody will actually run it, and a signal or other external
++ * event cannot wake it up and insert it on the runqueue either.
++ */
++ p->state = TASK_NEW;
++
++ /*
++ * Make sure we do not leak PI boosting priority to the child.
++ */
++ p->prio = current->normal_prio;
++
++ /*
++ * Revert to default priority/policy on fork if requested.
++ */
++ if (unlikely(p->sched_reset_on_fork)) {
++ if (task_has_rt_policy(p)) {
++ p->policy = SCHED_NORMAL;
++ p->static_prio = NICE_TO_PRIO(0);
++ p->rt_priority = 0;
++ } else if (PRIO_TO_NICE(p->static_prio) < 0)
++ p->static_prio = NICE_TO_PRIO(0);
++
++ p->prio = p->normal_prio = normal_prio(p);
++
++ /*
++ * We don't need the reset flag anymore after the fork. It has
++ * fulfilled its duty:
++ */
++ p->sched_reset_on_fork = 0;
++ }
++
++ /*
++ * The child is not yet in the pid-hash so no cgroup attach races,
++ * and the cgroup is pinned to this child due to cgroup_fork()
++ * is ran before sched_fork().
++ *
++ * Silence PROVE_RCU.
++ */
++ raw_spin_lock_irqsave(&p->pi_lock, flags);
++ /*
++ * Share the timeslice between parent and child, thus the
++ * total amount of pending timeslices in the system doesn't change,
++ * resulting in more scheduling fairness.
++ */
++ rq = this_rq();
++ raw_spin_lock(&rq->lock);
++
++ rq->curr->time_slice /= 2;
++ p->time_slice = rq->curr->time_slice;
++#ifdef CONFIG_SCHED_HRTICK
++ hrtick_start(rq, rq->curr->time_slice);
++#endif
++
++ if (p->time_slice < RESCHED_NS) {
++ p->time_slice = sched_timeslice_ns;
++ resched_curr(rq);
++ }
++ sched_task_fork(p, rq);
++ raw_spin_unlock(&rq->lock);
++
++ rseq_migrate(p);
++ /*
++ * We're setting the CPU for the first time, we don't migrate,
++ * so use __set_task_cpu().
++ */
++ __set_task_cpu(p, cpu_of(rq));
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++
++#ifdef CONFIG_SCHED_INFO
++ if (unlikely(sched_info_on()))
++ memset(&p->sched_info, 0, sizeof(p->sched_info));
++#endif
++ init_task_preempt_count(p);
++
++ return 0;
++}
++
++void sched_post_fork(struct task_struct *p) {}
++
++#ifdef CONFIG_SCHEDSTATS
++
++DEFINE_STATIC_KEY_FALSE(sched_schedstats);
++static bool __initdata __sched_schedstats = false;
++
++static void set_schedstats(bool enabled)
++{
++ if (enabled)
++ static_branch_enable(&sched_schedstats);
++ else
++ static_branch_disable(&sched_schedstats);
++}
++
++void force_schedstat_enabled(void)
++{
++ if (!schedstat_enabled()) {
++ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n");
++ static_branch_enable(&sched_schedstats);
++ }
++}
++
++static int __init setup_schedstats(char *str)
++{
++ int ret = 0;
++ if (!str)
++ goto out;
++
++ /*
++ * This code is called before jump labels have been set up, so we can't
++ * change the static branch directly just yet. Instead set a temporary
++ * variable so init_schedstats() can do it later.
++ */
++ if (!strcmp(str, "enable")) {
++ __sched_schedstats = true;
++ ret = 1;
++ } else if (!strcmp(str, "disable")) {
++ __sched_schedstats = false;
++ ret = 1;
++ }
++out:
++ if (!ret)
++ pr_warn("Unable to parse schedstats=\n");
++
++ return ret;
++}
++__setup("schedstats=", setup_schedstats);
++
++static void __init init_schedstats(void)
++{
++ set_schedstats(__sched_schedstats);
++}
++
++#ifdef CONFIG_PROC_SYSCTL
++int sysctl_schedstats(struct ctl_table *table, int write,
++ void __user *buffer, size_t *lenp, loff_t *ppos)
++{
++ struct ctl_table t;
++ int err;
++ int state = static_branch_likely(&sched_schedstats);
++
++ if (write && !capable(CAP_SYS_ADMIN))
++ return -EPERM;
++
++ t = *table;
++ t.data = &state;
++ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
++ if (err < 0)
++ return err;
++ if (write)
++ set_schedstats(state);
++ return err;
++}
++#endif /* CONFIG_PROC_SYSCTL */
++#else /* !CONFIG_SCHEDSTATS */
++static inline void init_schedstats(void) {}
++#endif /* CONFIG_SCHEDSTATS */
++
++/*
++ * wake_up_new_task - wake up a newly created task for the first time.
++ *
++ * This function will do some initial scheduler statistics housekeeping
++ * that must be done for every newly created context, then puts the task
++ * on the runqueue and wakes it.
++ */
++void wake_up_new_task(struct task_struct *p)
++{
++ unsigned long flags;
++ struct rq *rq;
++
++ raw_spin_lock_irqsave(&p->pi_lock, flags);
++
++ p->state = TASK_RUNNING;
++
++ rq = cpu_rq(select_task_rq(p, this_rq()));
++#ifdef CONFIG_SMP
++ rseq_migrate(p);
++ /*
++ * Fork balancing, do it here and not earlier because:
++ * - cpus_ptr can change in the fork path
++ * - any previously selected CPU might disappear through hotplug
++ * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq,
++ * as we're not fully set-up yet.
++ */
++ __set_task_cpu(p, cpu_of(rq));
++#endif
++
++ raw_spin_lock(&rq->lock);
++
++ update_rq_clock(rq);
++ activate_task(p, rq);
++ trace_sched_wakeup_new(p);
++ check_preempt_curr(rq);
++
++ raw_spin_unlock(&rq->lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++}
++
++#ifdef CONFIG_PREEMPT_NOTIFIERS
++
++static DEFINE_STATIC_KEY_FALSE(preempt_notifier_key);
++
++void preempt_notifier_inc(void)
++{
++ static_branch_inc(&preempt_notifier_key);
++}
++EXPORT_SYMBOL_GPL(preempt_notifier_inc);
++
++void preempt_notifier_dec(void)
++{
++ static_branch_dec(&preempt_notifier_key);
++}
++EXPORT_SYMBOL_GPL(preempt_notifier_dec);
++
++/**
++ * preempt_notifier_register - tell me when current is being preempted & rescheduled
++ * @notifier: notifier struct to register
++ */
++void preempt_notifier_register(struct preempt_notifier *notifier)
++{
++ if (!static_branch_unlikely(&preempt_notifier_key))
++ WARN(1, "registering preempt_notifier while notifiers disabled\n");
++
++ hlist_add_head(¬ifier->link, ¤t->preempt_notifiers);
++}
++EXPORT_SYMBOL_GPL(preempt_notifier_register);
++
++/**
++ * preempt_notifier_unregister - no longer interested in preemption notifications
++ * @notifier: notifier struct to unregister
++ *
++ * This is *not* safe to call from within a preemption notifier.
++ */
++void preempt_notifier_unregister(struct preempt_notifier *notifier)
++{
++ hlist_del(¬ifier->link);
++}
++EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
++
++static void __fire_sched_in_preempt_notifiers(struct task_struct *curr)
++{
++ struct preempt_notifier *notifier;
++
++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
++ notifier->ops->sched_in(notifier, raw_smp_processor_id());
++}
++
++static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr)
++{
++ if (static_branch_unlikely(&preempt_notifier_key))
++ __fire_sched_in_preempt_notifiers(curr);
++}
++
++static void
++__fire_sched_out_preempt_notifiers(struct task_struct *curr,
++ struct task_struct *next)
++{
++ struct preempt_notifier *notifier;
++
++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
++ notifier->ops->sched_out(notifier, next);
++}
++
++static __always_inline void
++fire_sched_out_preempt_notifiers(struct task_struct *curr,
++ struct task_struct *next)
++{
++ if (static_branch_unlikely(&preempt_notifier_key))
++ __fire_sched_out_preempt_notifiers(curr, next);
++}
++
++#else /* !CONFIG_PREEMPT_NOTIFIERS */
++
++static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr)
++{
++}
++
++static inline void
++fire_sched_out_preempt_notifiers(struct task_struct *curr,
++ struct task_struct *next)
++{
++}
++
++#endif /* CONFIG_PREEMPT_NOTIFIERS */
++
++static inline void prepare_task(struct task_struct *next)
++{
++ /*
++ * Claim the task as running, we do this before switching to it
++ * such that any running task will have this set.
++ *
++ * See the ttwu() WF_ON_CPU case and its ordering comment.
++ */
++ WRITE_ONCE(next->on_cpu, 1);
++}
++
++static inline void finish_task(struct task_struct *prev)
++{
++#ifdef CONFIG_SMP
++ /*
++ * This must be the very last reference to @prev from this CPU. After
++ * p->on_cpu is cleared, the task can be moved to a different CPU. We
++ * must ensure this doesn't happen until the switch is completely
++ * finished.
++ *
++ * In particular, the load of prev->state in finish_task_switch() must
++ * happen before this.
++ *
++ * Pairs with the smp_cond_load_acquire() in try_to_wake_up().
++ */
++ smp_store_release(&prev->on_cpu, 0);
++#else
++ prev->on_cpu = 0;
++#endif
++}
++
++#ifdef CONFIG_SMP
++
++static void do_balance_callbacks(struct rq *rq, struct callback_head *head)
++{
++ void (*func)(struct rq *rq);
++ struct callback_head *next;
++
++ lockdep_assert_held(&rq->lock);
++
++ while (head) {
++ func = (void (*)(struct rq *))head->func;
++ next = head->next;
++ head->next = NULL;
++ head = next;
++
++ func(rq);
++ }
++}
++
++static void balance_push(struct rq *rq);
++
++struct callback_head balance_push_callback = {
++ .next = NULL,
++ .func = (void (*)(struct callback_head *))balance_push,
++};
++
++static inline struct callback_head *splice_balance_callbacks(struct rq *rq)
++{
++ struct callback_head *head = rq->balance_callback;
++
++ if (head) {
++ lockdep_assert_held(&rq->lock);
++ rq->balance_callback = NULL;
++ }
++
++ return head;
++}
++
++static void __balance_callbacks(struct rq *rq)
++{
++ do_balance_callbacks(rq, splice_balance_callbacks(rq));
++}
++
++static inline void balance_callbacks(struct rq *rq, struct callback_head *head)
++{
++ unsigned long flags;
++
++ if (unlikely(head)) {
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ do_balance_callbacks(rq, head);
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++ }
++}
++
++#else
++
++static inline void __balance_callbacks(struct rq *rq)
++{
++}
++
++static inline struct callback_head *splice_balance_callbacks(struct rq *rq)
++{
++ return NULL;
++}
++
++static inline void balance_callbacks(struct rq *rq, struct callback_head *head)
++{
++}
++
++#endif
++
++static inline void
++prepare_lock_switch(struct rq *rq, struct task_struct *next)
++{
++ /*
++ * Since the runqueue lock will be released by the next
++ * task (which is an invalid locking op but in the case
++ * of the scheduler it's an obvious special-case), so we
++ * do an early lockdep release here:
++ */
++ spin_release(&rq->lock.dep_map, _THIS_IP_);
++#ifdef CONFIG_DEBUG_SPINLOCK
++ /* this is a valid case when another task releases the spinlock */
++ rq->lock.owner = next;
++#endif
++}
++
++static inline void finish_lock_switch(struct rq *rq)
++{
++ /*
++ * If we are tracking spinlock dependencies then we have to
++ * fix up the runqueue lock - which gets 'carried over' from
++ * prev into current:
++ */
++ spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
++ __balance_callbacks(rq);
++ raw_spin_unlock_irq(&rq->lock);
++}
++
++/*
++ * NOP if the arch has not defined these:
++ */
++
++#ifndef prepare_arch_switch
++# define prepare_arch_switch(next) do { } while (0)
++#endif
++
++#ifndef finish_arch_post_lock_switch
++# define finish_arch_post_lock_switch() do { } while (0)
++#endif
++
++static inline void kmap_local_sched_out(void)
++{
++#ifdef CONFIG_KMAP_LOCAL
++ if (unlikely(current->kmap_ctrl.idx))
++ __kmap_local_sched_out();
++#endif
++}
++
++static inline void kmap_local_sched_in(void)
++{
++#ifdef CONFIG_KMAP_LOCAL
++ if (unlikely(current->kmap_ctrl.idx))
++ __kmap_local_sched_in();
++#endif
++}
++
++/**
++ * prepare_task_switch - prepare to switch tasks
++ * @rq: the runqueue preparing to switch
++ * @next: the task we are going to switch to.
++ *
++ * This is called with the rq lock held and interrupts off. It must
++ * be paired with a subsequent finish_task_switch after the context
++ * switch.
++ *
++ * prepare_task_switch sets up locking and calls architecture specific
++ * hooks.
++ */
++static inline void
++prepare_task_switch(struct rq *rq, struct task_struct *prev,
++ struct task_struct *next)
++{
++ kcov_prepare_switch(prev);
++ sched_info_switch(rq, prev, next);
++ perf_event_task_sched_out(prev, next);
++ rseq_preempt(prev);
++ fire_sched_out_preempt_notifiers(prev, next);
++ kmap_local_sched_out();
++ prepare_task(next);
++ prepare_arch_switch(next);
++}
++
++/**
++ * finish_task_switch - clean up after a task-switch
++ * @rq: runqueue associated with task-switch
++ * @prev: the thread we just switched away from.
++ *
++ * finish_task_switch must be called after the context switch, paired
++ * with a prepare_task_switch call before the context switch.
++ * finish_task_switch will reconcile locking set up by prepare_task_switch,
++ * and do any other architecture-specific cleanup actions.
++ *
++ * Note that we may have delayed dropping an mm in context_switch(). If
++ * so, we finish that here outside of the runqueue lock. (Doing it
++ * with the lock held can cause deadlocks; see schedule() for
++ * details.)
++ *
++ * The context switch have flipped the stack from under us and restored the
++ * local variables which were saved when this task called schedule() in the
++ * past. prev == current is still correct but we need to recalculate this_rq
++ * because prev may have moved to another CPU.
++ */
++static struct rq *finish_task_switch(struct task_struct *prev)
++ __releases(rq->lock)
++{
++ struct rq *rq = this_rq();
++ struct mm_struct *mm = rq->prev_mm;
++ long prev_state;
++
++ /*
++ * The previous task will have left us with a preempt_count of 2
++ * because it left us after:
++ *
++ * schedule()
++ * preempt_disable(); // 1
++ * __schedule()
++ * raw_spin_lock_irq(&rq->lock) // 2
++ *
++ * Also, see FORK_PREEMPT_COUNT.
++ */
++ if (WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET,
++ "corrupted preempt_count: %s/%d/0x%x\n",
++ current->comm, current->pid, preempt_count()))
++ preempt_count_set(FORK_PREEMPT_COUNT);
++
++ rq->prev_mm = NULL;
++
++ /*
++ * A task struct has one reference for the use as "current".
++ * If a task dies, then it sets TASK_DEAD in tsk->state and calls
++ * schedule one last time. The schedule call will never return, and
++ * the scheduled task must drop that reference.
++ *
++ * We must observe prev->state before clearing prev->on_cpu (in
++ * finish_task), otherwise a concurrent wakeup can get prev
++ * running on another CPU and we could rave with its RUNNING -> DEAD
++ * transition, resulting in a double drop.
++ */
++ prev_state = prev->state;
++ vtime_task_switch(prev);
++ perf_event_task_sched_in(prev, current);
++ finish_task(prev);
++ finish_lock_switch(rq);
++ finish_arch_post_lock_switch();
++ kcov_finish_switch(current);
++ /*
++ * kmap_local_sched_out() is invoked with rq::lock held and
++ * interrupts disabled. There is no requirement for that, but the
++ * sched out code does not have an interrupt enabled section.
++ * Restoring the maps on sched in does not require interrupts being
++ * disabled either.
++ */
++ kmap_local_sched_in();
++
++ fire_sched_in_preempt_notifiers(current);
++ /*
++ * When switching through a kernel thread, the loop in
++ * membarrier_{private,global}_expedited() may have observed that
++ * kernel thread and not issued an IPI. It is therefore possible to
++ * schedule between user->kernel->user threads without passing though
++ * switch_mm(). Membarrier requires a barrier after storing to
++ * rq->curr, before returning to userspace, so provide them here:
++ *
++ * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly
++ * provided by mmdrop(),
++ * - a sync_core for SYNC_CORE.
++ */
++ if (mm) {
++ membarrier_mm_sync_core_before_usermode(mm);
++ mmdrop(mm);
++ }
++ if (unlikely(prev_state == TASK_DEAD)) {
++ /*
++ * Remove function-return probe instances associated with this
++ * task and put them back on the free list.
++ */
++ kprobe_flush_task(prev);
++
++ /* Task is done with its stack. */
++ put_task_stack(prev);
++
++ put_task_struct_rcu_user(prev);
++ }
++
++ tick_nohz_task_switch();
++ return rq;
++}
++
++/**
++ * schedule_tail - first thing a freshly forked thread must call.
++ * @prev: the thread we just switched away from.
++ */
++asmlinkage __visible void schedule_tail(struct task_struct *prev)
++ __releases(rq->lock)
++{
++ struct rq *rq;
++
++ /*
++ * New tasks start with FORK_PREEMPT_COUNT, see there and
++ * finish_task_switch() for details.
++ *
++ * finish_task_switch() will drop rq->lock() and lower preempt_count
++ * and the preempt_enable() will end up enabling preemption (on
++ * PREEMPT_COUNT kernels).
++ */
++
++ rq = finish_task_switch(prev);
++ preempt_enable();
++
++ if (current->set_child_tid)
++ put_user(task_pid_vnr(current), current->set_child_tid);
++
++ calculate_sigpending();
++}
++
++/*
++ * context_switch - switch to the new MM and the new thread's register state.
++ */
++static __always_inline struct rq *
++context_switch(struct rq *rq, struct task_struct *prev,
++ struct task_struct *next)
++{
++ prepare_task_switch(rq, prev, next);
++
++ /*
++ * For paravirt, this is coupled with an exit in switch_to to
++ * combine the page table reload and the switch backend into
++ * one hypercall.
++ */
++ arch_start_context_switch(prev);
++
++ /*
++ * kernel -> kernel lazy + transfer active
++ * user -> kernel lazy + mmgrab() active
++ *
++ * kernel -> user switch + mmdrop() active
++ * user -> user switch
++ */
++ if (!next->mm) { // to kernel
++ enter_lazy_tlb(prev->active_mm, next);
++
++ next->active_mm = prev->active_mm;
++ if (prev->mm) // from user
++ mmgrab(prev->active_mm);
++ else
++ prev->active_mm = NULL;
++ } else { // to user
++ membarrier_switch_mm(rq, prev->active_mm, next->mm);
++ /*
++ * sys_membarrier() requires an smp_mb() between setting
++ * rq->curr / membarrier_switch_mm() and returning to userspace.
++ *
++ * The below provides this either through switch_mm(), or in
++ * case 'prev->active_mm == next->mm' through
++ * finish_task_switch()'s mmdrop().
++ */
++ switch_mm_irqs_off(prev->active_mm, next->mm, next);
++
++ if (!prev->mm) { // from kernel
++ /* will mmdrop() in finish_task_switch(). */
++ rq->prev_mm = prev->active_mm;
++ prev->active_mm = NULL;
++ }
++ }
++
++ prepare_lock_switch(rq, next);
++
++ /* Here we just switch the register state and the stack. */
++ switch_to(prev, next, prev);
++ barrier();
++
++ return finish_task_switch(prev);
++}
++
++/*
++ * nr_running, nr_uninterruptible and nr_context_switches:
++ *
++ * externally visible scheduler statistics: current number of runnable
++ * threads, total number of context switches performed since bootup.
++ */
++unsigned long nr_running(void)
++{
++ unsigned long i, sum = 0;
++
++ for_each_online_cpu(i)
++ sum += cpu_rq(i)->nr_running;
++
++ return sum;
++}
++
++/*
++ * Check if only the current task is running on the CPU.
++ *
++ * Caution: this function does not check that the caller has disabled
++ * preemption, thus the result might have a time-of-check-to-time-of-use
++ * race. The caller is responsible to use it correctly, for example:
++ *
++ * - from a non-preemptible section (of course)
++ *
++ * - from a thread that is bound to a single CPU
++ *
++ * - in a loop with very short iterations (e.g. a polling loop)
++ */
++bool single_task_running(void)
++{
++ return raw_rq()->nr_running == 1;
++}
++EXPORT_SYMBOL(single_task_running);
++
++unsigned long long nr_context_switches(void)
++{
++ int i;
++ unsigned long long sum = 0;
++
++ for_each_possible_cpu(i)
++ sum += cpu_rq(i)->nr_switches;
++
++ return sum;
++}
++
++/*
++ * Consumers of these two interfaces, like for example the cpuidle menu
++ * governor, are using nonsensical data. Preferring shallow idle state selection
++ * for a CPU that has IO-wait which might not even end up running the task when
++ * it does become runnable.
++ */
++
++unsigned long nr_iowait_cpu(int cpu)
++{
++ return atomic_read(&cpu_rq(cpu)->nr_iowait);
++}
++
++/*
++ * IO-wait accounting, and how it's mostly bollocks (on SMP).
++ *
++ * The idea behind IO-wait account is to account the idle time that we could
++ * have spend running if it were not for IO. That is, if we were to improve the
++ * storage performance, we'd have a proportional reduction in IO-wait time.
++ *
++ * This all works nicely on UP, where, when a task blocks on IO, we account
++ * idle time as IO-wait, because if the storage were faster, it could've been
++ * running and we'd not be idle.
++ *
++ * This has been extended to SMP, by doing the same for each CPU. This however
++ * is broken.
++ *
++ * Imagine for instance the case where two tasks block on one CPU, only the one
++ * CPU will have IO-wait accounted, while the other has regular idle. Even
++ * though, if the storage were faster, both could've ran at the same time,
++ * utilising both CPUs.
++ *
++ * This means, that when looking globally, the current IO-wait accounting on
++ * SMP is a lower bound, by reason of under accounting.
++ *
++ * Worse, since the numbers are provided per CPU, they are sometimes
++ * interpreted per CPU, and that is nonsensical. A blocked task isn't strictly
++ * associated with any one particular CPU, it can wake to another CPU than it
++ * blocked on. This means the per CPU IO-wait number is meaningless.
++ *
++ * Task CPU affinities can make all that even more 'interesting'.
++ */
++
++unsigned long nr_iowait(void)
++{
++ unsigned long i, sum = 0;
++
++ for_each_possible_cpu(i)
++ sum += nr_iowait_cpu(i);
++
++ return sum;
++}
++
++#ifdef CONFIG_SMP
++
++/*
++ * sched_exec - execve() is a valuable balancing opportunity, because at
++ * this point the task has the smallest effective memory and cache
++ * footprint.
++ */
++void sched_exec(void)
++{
++ struct task_struct *p = current;
++ unsigned long flags;
++ int dest_cpu;
++ struct rq *rq;
++
++ raw_spin_lock_irqsave(&p->pi_lock, flags);
++ rq = this_rq();
++
++ if (rq != task_rq(p) || rq->nr_running < 2)
++ goto unlock;
++
++ dest_cpu = select_task_rq(p, task_rq(p));
++ if (dest_cpu == smp_processor_id())
++ goto unlock;
++
++ if (likely(cpu_active(dest_cpu))) {
++ struct migration_arg arg = { p, dest_cpu };
++
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++ stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg);
++ return;
++ }
++unlock:
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++}
++
++#endif
++
++DEFINE_PER_CPU(struct kernel_stat, kstat);
++DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
++
++EXPORT_PER_CPU_SYMBOL(kstat);
++EXPORT_PER_CPU_SYMBOL(kernel_cpustat);
++
++static inline void update_curr(struct rq *rq, struct task_struct *p)
++{
++ s64 ns = rq->clock_task - p->last_ran;
++
++ p->sched_time += ns;
++ account_group_exec_runtime(p, ns);
++
++ p->time_slice -= ns;
++ p->last_ran = rq->clock_task;
++}
++
++/*
++ * Return accounted runtime for the task.
++ * Return separately the current's pending runtime that have not been
++ * accounted yet.
++ */
++unsigned long long task_sched_runtime(struct task_struct *p)
++{
++ unsigned long flags;
++ struct rq *rq;
++ raw_spinlock_t *lock;
++ u64 ns;
++
++#if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
++ /*
++ * 64-bit doesn't need locks to atomically read a 64-bit value.
++ * So we have a optimization chance when the task's delta_exec is 0.
++ * Reading ->on_cpu is racy, but this is ok.
++ *
++ * If we race with it leaving CPU, we'll take a lock. So we're correct.
++ * If we race with it entering CPU, unaccounted time is 0. This is
++ * indistinguishable from the read occurring a few cycles earlier.
++ * If we see ->on_cpu without ->on_rq, the task is leaving, and has
++ * been accounted, so we're correct here as well.
++ */
++ if (!p->on_cpu || !task_on_rq_queued(p))
++ return tsk_seruntime(p);
++#endif
++
++ rq = task_access_lock_irqsave(p, &lock, &flags);
++ /*
++ * Must be ->curr _and_ ->on_rq. If dequeued, we would
++ * project cycles that may never be accounted to this
++ * thread, breaking clock_gettime().
++ */
++ if (p == rq->curr && task_on_rq_queued(p)) {
++ update_rq_clock(rq);
++ update_curr(rq, p);
++ }
++ ns = tsk_seruntime(p);
++ task_access_unlock_irqrestore(p, lock, &flags);
++
++ return ns;
++}
++
++/* This manages tasks that have run out of timeslice during a scheduler_tick */
++static inline void scheduler_task_tick(struct rq *rq)
++{
++ struct task_struct *p = rq->curr;
++
++ if (is_idle_task(p))
++ return;
++
++ update_curr(rq, p);
++ cpufreq_update_util(rq, 0);
++
++ /*
++ * Tasks have less than RESCHED_NS of time slice left they will be
++ * rescheduled.
++ */
++ if (p->time_slice >= RESCHED_NS)
++ return;
++ set_tsk_need_resched(p);
++ set_preempt_need_resched();
++}
++
++/*
++ * This function gets called by the timer code, with HZ frequency.
++ * We call it with interrupts disabled.
++ */
++void scheduler_tick(void)
++{
++ int cpu __maybe_unused = smp_processor_id();
++ struct rq *rq = cpu_rq(cpu);
++
++ arch_scale_freq_tick();
++ sched_clock_tick();
++
++ raw_spin_lock(&rq->lock);
++ update_rq_clock(rq);
++
++ scheduler_task_tick(rq);
++ calc_global_load_tick(rq);
++ psi_task_tick(rq);
++
++ rq->last_tick = rq->clock;
++ raw_spin_unlock(&rq->lock);
++
++ perf_event_task_tick();
++}
++
++#ifdef CONFIG_SCHED_SMT
++static inline int active_load_balance_cpu_stop(void *data)
++{
++ struct rq *rq = this_rq();
++ struct task_struct *p = data;
++ cpumask_t tmp;
++ unsigned long flags;
++
++ local_irq_save(flags);
++
++ raw_spin_lock(&p->pi_lock);
++ raw_spin_lock(&rq->lock);
++
++ rq->active_balance = 0;
++ /* _something_ may have changed the task, double check again */
++ if (task_on_rq_queued(p) && task_rq(p) == rq &&
++ cpumask_and(&tmp, p->cpus_ptr, &sched_sg_idle_mask) &&
++ !is_migration_disabled(p)) {
++ int cpu = cpu_of(rq);
++ int dcpu = __best_mask_cpu(cpu, &tmp,
++ per_cpu(sched_cpu_llc_mask, cpu));
++ rq = move_queued_task(rq, p, dcpu);
++ }
++
++ raw_spin_unlock(&rq->lock);
++ raw_spin_unlock(&p->pi_lock);
++
++ local_irq_restore(flags);
++
++ return 0;
++}
++
++/* sg_balance_trigger - trigger slibing group balance for @cpu */
++static inline int sg_balance_trigger(const int cpu)
++{
++ struct rq *rq= cpu_rq(cpu);
++ unsigned long flags;
++ struct task_struct *curr;
++ int res;
++
++ if (!raw_spin_trylock_irqsave(&rq->lock, flags))
++ return 0;
++ curr = rq->curr;
++ res = (!is_idle_task(curr)) && (1 == rq->nr_running) &&\
++ cpumask_intersects(curr->cpus_ptr, &sched_sg_idle_mask) &&\
++ !is_migration_disabled(curr) && (!rq->active_balance);
++
++ if (res)
++ rq->active_balance = 1;
++
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++
++ if (res)
++ stop_one_cpu_nowait(cpu, active_load_balance_cpu_stop,
++ curr, &rq->active_balance_work);
++ return res;
++}
++
++/*
++ * sg_balance_check - slibing group balance check for run queue @rq
++ */
++static inline void sg_balance_check(struct rq *rq)
++{
++ cpumask_t chk;
++ int cpu;
++
++ /* exit when no sg in idle */
++ if (cpumask_empty(&sched_sg_idle_mask))
++ return;
++
++ cpu = cpu_of(rq);
++ /*
++ * Only cpu in slibing idle group will do the checking and then
++ * find potential cpus which can migrate the current running task
++ */
++ if (cpumask_test_cpu(cpu, &sched_sg_idle_mask) &&
++ cpumask_andnot(&chk, cpu_online_mask, &sched_rq_pending_mask) &&
++ cpumask_andnot(&chk, &chk, &sched_rq_watermark[IDLE_WM])) {
++ int i, tried = 0;
++
++ for_each_cpu_wrap(i, &chk, cpu) {
++ if (cpumask_subset(cpu_smt_mask(i), &chk)) {
++ if (sg_balance_trigger(i))
++ return;
++ if (tried)
++ return;
++ tried++;
++ }
++ }
++ }
++}
++#endif /* CONFIG_SCHED_SMT */
++
++#ifdef CONFIG_NO_HZ_FULL
++
++struct tick_work {
++ int cpu;
++ atomic_t state;
++ struct delayed_work work;
++};
++/* Values for ->state, see diagram below. */
++#define TICK_SCHED_REMOTE_OFFLINE 0
++#define TICK_SCHED_REMOTE_OFFLINING 1
++#define TICK_SCHED_REMOTE_RUNNING 2
++
++/*
++ * State diagram for ->state:
++ *
++ *
++ * TICK_SCHED_REMOTE_OFFLINE
++ * | ^
++ * | |
++ * | | sched_tick_remote()
++ * | |
++ * | |
++ * +--TICK_SCHED_REMOTE_OFFLINING
++ * | ^
++ * | |
++ * sched_tick_start() | | sched_tick_stop()
++ * | |
++ * V |
++ * TICK_SCHED_REMOTE_RUNNING
++ *
++ *
++ * Other transitions get WARN_ON_ONCE(), except that sched_tick_remote()
++ * and sched_tick_start() are happy to leave the state in RUNNING.
++ */
++
++static struct tick_work __percpu *tick_work_cpu;
++
++static void sched_tick_remote(struct work_struct *work)
++{
++ struct delayed_work *dwork = to_delayed_work(work);
++ struct tick_work *twork = container_of(dwork, struct tick_work, work);
++ int cpu = twork->cpu;
++ struct rq *rq = cpu_rq(cpu);
++ struct task_struct *curr;
++ unsigned long flags;
++ u64 delta;
++ int os;
++
++ /*
++ * Handle the tick only if it appears the remote CPU is running in full
++ * dynticks mode. The check is racy by nature, but missing a tick or
++ * having one too much is no big deal because the scheduler tick updates
++ * statistics and checks timeslices in a time-independent way, regardless
++ * of when exactly it is running.
++ */
++ if (!tick_nohz_tick_stopped_cpu(cpu))
++ goto out_requeue;
++
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ curr = rq->curr;
++ if (cpu_is_offline(cpu))
++ goto out_unlock;
++
++ update_rq_clock(rq);
++ if (!is_idle_task(curr)) {
++ /*
++ * Make sure the next tick runs within a reasonable
++ * amount of time.
++ */
++ delta = rq_clock_task(rq) - curr->last_ran;
++ WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);
++ }
++ scheduler_task_tick(rq);
++
++ calc_load_nohz_remote(rq);
++out_unlock:
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++
++out_requeue:
++ /*
++ * Run the remote tick once per second (1Hz). This arbitrary
++ * frequency is large enough to avoid overload but short enough
++ * to keep scheduler internal stats reasonably up to date. But
++ * first update state to reflect hotplug activity if required.
++ */
++ os = atomic_fetch_add_unless(&twork->state, -1, TICK_SCHED_REMOTE_RUNNING);
++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_OFFLINE);
++ if (os == TICK_SCHED_REMOTE_RUNNING)
++ queue_delayed_work(system_unbound_wq, dwork, HZ);
++}
++
++static void sched_tick_start(int cpu)
++{
++ int os;
++ struct tick_work *twork;
++
++ if (housekeeping_cpu(cpu, HK_FLAG_TICK))
++ return;
++
++ WARN_ON_ONCE(!tick_work_cpu);
++
++ twork = per_cpu_ptr(tick_work_cpu, cpu);
++ os = atomic_xchg(&twork->state, TICK_SCHED_REMOTE_RUNNING);
++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_RUNNING);
++ if (os == TICK_SCHED_REMOTE_OFFLINE) {
++ twork->cpu = cpu;
++ INIT_DELAYED_WORK(&twork->work, sched_tick_remote);
++ queue_delayed_work(system_unbound_wq, &twork->work, HZ);
++ }
++}
++
++#ifdef CONFIG_HOTPLUG_CPU
++static void sched_tick_stop(int cpu)
++{
++ struct tick_work *twork;
++
++ if (housekeeping_cpu(cpu, HK_FLAG_TICK))
++ return;
++
++ WARN_ON_ONCE(!tick_work_cpu);
++
++ twork = per_cpu_ptr(tick_work_cpu, cpu);
++ cancel_delayed_work_sync(&twork->work);
++}
++#endif /* CONFIG_HOTPLUG_CPU */
++
++int __init sched_tick_offload_init(void)
++{
++ tick_work_cpu = alloc_percpu(struct tick_work);
++ BUG_ON(!tick_work_cpu);
++ return 0;
++}
++
++#else /* !CONFIG_NO_HZ_FULL */
++static inline void sched_tick_start(int cpu) { }
++static inline void sched_tick_stop(int cpu) { }
++#endif
++
++#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \
++ defined(CONFIG_PREEMPT_TRACER))
++/*
++ * If the value passed in is equal to the current preempt count
++ * then we just disabled preemption. Start timing the latency.
++ */
++static inline void preempt_latency_start(int val)
++{
++ if (preempt_count() == val) {
++ unsigned long ip = get_lock_parent_ip();
++#ifdef CONFIG_DEBUG_PREEMPT
++ current->preempt_disable_ip = ip;
++#endif
++ trace_preempt_off(CALLER_ADDR0, ip);
++ }
++}
++
++void preempt_count_add(int val)
++{
++#ifdef CONFIG_DEBUG_PREEMPT
++ /*
++ * Underflow?
++ */
++ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
++ return;
++#endif
++ __preempt_count_add(val);
++#ifdef CONFIG_DEBUG_PREEMPT
++ /*
++ * Spinlock count overflowing soon?
++ */
++ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
++ PREEMPT_MASK - 10);
++#endif
++ preempt_latency_start(val);
++}
++EXPORT_SYMBOL(preempt_count_add);
++NOKPROBE_SYMBOL(preempt_count_add);
++
++/*
++ * If the value passed in equals to the current preempt count
++ * then we just enabled preemption. Stop timing the latency.
++ */
++static inline void preempt_latency_stop(int val)
++{
++ if (preempt_count() == val)
++ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
++}
++
++void preempt_count_sub(int val)
++{
++#ifdef CONFIG_DEBUG_PREEMPT
++ /*
++ * Underflow?
++ */
++ if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
++ return;
++ /*
++ * Is the spinlock portion underflowing?
++ */
++ if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
++ !(preempt_count() & PREEMPT_MASK)))
++ return;
++#endif
++
++ preempt_latency_stop(val);
++ __preempt_count_sub(val);
++}
++EXPORT_SYMBOL(preempt_count_sub);
++NOKPROBE_SYMBOL(preempt_count_sub);
++
++#else
++static inline void preempt_latency_start(int val) { }
++static inline void preempt_latency_stop(int val) { }
++#endif
++
++static inline unsigned long get_preempt_disable_ip(struct task_struct *p)
++{
++#ifdef CONFIG_DEBUG_PREEMPT
++ return p->preempt_disable_ip;
++#else
++ return 0;
++#endif
++}
++
++/*
++ * Print scheduling while atomic bug:
++ */
++static noinline void __schedule_bug(struct task_struct *prev)
++{
++ /* Save this before calling printk(), since that will clobber it */
++ unsigned long preempt_disable_ip = get_preempt_disable_ip(current);
++
++ if (oops_in_progress)
++ return;
++
++ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
++ prev->comm, prev->pid, preempt_count());
++
++ debug_show_held_locks(prev);
++ print_modules();
++ if (irqs_disabled())
++ print_irqtrace_events(prev);
++ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)
++ && in_atomic_preempt_off()) {
++ pr_err("Preemption disabled at:");
++ print_ip_sym(KERN_ERR, preempt_disable_ip);
++ }
++ if (panic_on_warn)
++ panic("scheduling while atomic\n");
++
++ dump_stack();
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
++}
++
++/*
++ * Various schedule()-time debugging checks and statistics:
++ */
++static inline void schedule_debug(struct task_struct *prev, bool preempt)
++{
++#ifdef CONFIG_SCHED_STACK_END_CHECK
++ if (task_stack_end_corrupted(prev))
++ panic("corrupted stack end detected inside scheduler\n");
++
++ if (task_scs_end_corrupted(prev))
++ panic("corrupted shadow stack detected inside scheduler\n");
++#endif
++
++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
++ if (!preempt && prev->state && prev->non_block_count) {
++ printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n",
++ prev->comm, prev->pid, prev->non_block_count);
++ dump_stack();
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
++ }
++#endif
++
++ if (unlikely(in_atomic_preempt_off())) {
++ __schedule_bug(prev);
++ preempt_count_set(PREEMPT_DISABLED);
++ }
++ rcu_sleep_check();
++ SCHED_WARN_ON(ct_state() == CONTEXT_USER);
++
++ profile_hit(SCHED_PROFILING, __builtin_return_address(0));
++
++ schedstat_inc(this_rq()->sched_count);
++}
++
++/*
++ * Compile time debug macro
++ * #define ALT_SCHED_DEBUG
++ */
++
++#ifdef ALT_SCHED_DEBUG
++void alt_sched_debug(void)
++{
++ printk(KERN_INFO "sched: pending: 0x%04lx, idle: 0x%04lx, sg_idle: 0x%04lx\n",
++ sched_rq_pending_mask.bits[0],
++ sched_rq_watermark[IDLE_WM].bits[0],
++ sched_sg_idle_mask.bits[0]);
++}
++#else
++inline void alt_sched_debug(void) {}
++#endif
++
++#ifdef CONFIG_SMP
++
++#define SCHED_RQ_NR_MIGRATION (32U)
++/*
++ * Migrate pending tasks in @rq to @dest_cpu
++ * Will try to migrate mininal of half of @rq nr_running tasks and
++ * SCHED_RQ_NR_MIGRATION to @dest_cpu
++ */
++static inline int
++migrate_pending_tasks(struct rq *rq, struct rq *dest_rq, const int dest_cpu)
++{
++ struct task_struct *p, *skip = rq->curr;
++ int nr_migrated = 0;
++ int nr_tries = min(rq->nr_running / 2, SCHED_RQ_NR_MIGRATION);
++
++ while (skip != rq->idle && nr_tries &&
++ (p = sched_rq_next_task(skip, rq)) != rq->idle) {
++ skip = sched_rq_next_task(p, rq);
++ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) {
++ __SCHED_DEQUEUE_TASK(p, rq, 0, );
++ set_task_cpu(p, dest_cpu);
++ __SCHED_ENQUEUE_TASK(p, dest_rq, 0);
++ nr_migrated++;
++ }
++ nr_tries--;
++ }
++
++ return nr_migrated;
++}
++
++static inline int take_other_rq_tasks(struct rq *rq, int cpu)
++{
++ struct cpumask *affinity_mask, *end_mask;
++
++ if (unlikely(!rq->online))
++ return 0;
++
++ if (cpumask_empty(&sched_rq_pending_mask))
++ return 0;
++
++ affinity_mask = per_cpu(sched_cpu_affinity_masks, cpu) + 1;
++ end_mask = per_cpu(sched_cpu_affinity_end_mask, cpu);
++ do {
++ int i;
++ for_each_cpu_and(i, &sched_rq_pending_mask, affinity_mask) {
++ int nr_migrated;
++ struct rq *src_rq;
++
++ src_rq = cpu_rq(i);
++ if (!do_raw_spin_trylock(&src_rq->lock))
++ continue;
++ spin_acquire(&src_rq->lock.dep_map,
++ SINGLE_DEPTH_NESTING, 1, _RET_IP_);
++
++ if ((nr_migrated = migrate_pending_tasks(src_rq, rq, cpu))) {
++ src_rq->nr_running -= nr_migrated;
++#ifdef CONFIG_SMP
++ if (src_rq->nr_running < 2)
++ cpumask_clear_cpu(i, &sched_rq_pending_mask);
++#endif
++ rq->nr_running += nr_migrated;
++#ifdef CONFIG_SMP
++ if (rq->nr_running > 1)
++ cpumask_set_cpu(cpu, &sched_rq_pending_mask);
++#endif
++ update_sched_rq_watermark(rq);
++ cpufreq_update_util(rq, 0);
++
++ spin_release(&src_rq->lock.dep_map, _RET_IP_);
++ do_raw_spin_unlock(&src_rq->lock);
++
++ return 1;
++ }
++
++ spin_release(&src_rq->lock.dep_map, _RET_IP_);
++ do_raw_spin_unlock(&src_rq->lock);
++ }
++ } while (++affinity_mask < end_mask);
++
++ return 0;
++}
++#endif
++
++/*
++ * Timeslices below RESCHED_NS are considered as good as expired as there's no
++ * point rescheduling when there's so little time left.
++ */
++static inline void check_curr(struct task_struct *p, struct rq *rq)
++{
++ if (unlikely(rq->idle == p))
++ return;
++
++ update_curr(rq, p);
++
++ if (p->time_slice < RESCHED_NS)
++ time_slice_expired(p, rq);
++}
++
++static inline struct task_struct *
++choose_next_task(struct rq *rq, int cpu, struct task_struct *prev)
++{
++ struct task_struct *next;
++
++ if (unlikely(rq->skip)) {
++ next = rq_runnable_task(rq);
++ if (next == rq->idle) {
++#ifdef CONFIG_SMP
++ if (!take_other_rq_tasks(rq, cpu)) {
++#endif
++ rq->skip = NULL;
++ schedstat_inc(rq->sched_goidle);
++ return next;
++#ifdef CONFIG_SMP
++ }
++ next = rq_runnable_task(rq);
++#endif
++ }
++ rq->skip = NULL;
++#ifdef CONFIG_HIGH_RES_TIMERS
++ hrtick_start(rq, next->time_slice);
++#endif
++ return next;
++ }
++
++ next = sched_rq_first_task(rq);
++ if (next == rq->idle) {
++#ifdef CONFIG_SMP
++ if (!take_other_rq_tasks(rq, cpu)) {
++#endif
++ schedstat_inc(rq->sched_goidle);
++ /*printk(KERN_INFO "sched: choose_next_task(%d) idle %px\n", cpu, next);*/
++ return next;
++#ifdef CONFIG_SMP
++ }
++ next = sched_rq_first_task(rq);
++#endif
++ }
++#ifdef CONFIG_HIGH_RES_TIMERS
++ hrtick_start(rq, next->time_slice);
++#endif
++ /*printk(KERN_INFO "sched: choose_next_task(%d) next %px\n", cpu,
++ * next);*/
++ return next;
++}
++
++/*
++ * schedule() is the main scheduler function.
++ *
++ * The main means of driving the scheduler and thus entering this function are:
++ *
++ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc.
++ *
++ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return
++ * paths. For example, see arch/x86/entry_64.S.
++ *
++ * To drive preemption between tasks, the scheduler sets the flag in timer
++ * interrupt handler scheduler_tick().
++ *
++ * 3. Wakeups don't really cause entry into schedule(). They add a
++ * task to the run-queue and that's it.
++ *
++ * Now, if the new task added to the run-queue preempts the current
++ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
++ * called on the nearest possible occasion:
++ *
++ * - If the kernel is preemptible (CONFIG_PREEMPTION=y):
++ *
++ * - in syscall or exception context, at the next outmost
++ * preempt_enable(). (this might be as soon as the wake_up()'s
++ * spin_unlock()!)
++ *
++ * - in IRQ context, return from interrupt-handler to
++ * preemptible context
++ *
++ * - If the kernel is not preemptible (CONFIG_PREEMPTION is not set)
++ * then at the next:
++ *
++ * - cond_resched() call
++ * - explicit schedule() call
++ * - return from syscall or exception to user-space
++ * - return from interrupt-handler to user-space
++ *
++ * WARNING: must be called with preemption disabled!
++ */
++static void __sched notrace __schedule(bool preempt)
++{
++ struct task_struct *prev, *next;
++ unsigned long *switch_count;
++ unsigned long prev_state;
++ struct rq *rq;
++ int cpu;
++
++ cpu = smp_processor_id();
++ rq = cpu_rq(cpu);
++ prev = rq->curr;
++
++ schedule_debug(prev, preempt);
++
++ /* by passing sched_feat(HRTICK) checking which Alt schedule FW doesn't support */
++ hrtick_clear(rq);
++
++ local_irq_disable();
++ rcu_note_context_switch(preempt);
++
++ /*
++ * Make sure that signal_pending_state()->signal_pending() below
++ * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
++ * done by the caller to avoid the race with signal_wake_up():
++ *
++ * __set_current_state(@state) signal_wake_up()
++ * schedule() set_tsk_thread_flag(p, TIF_SIGPENDING)
++ * wake_up_state(p, state)
++ * LOCK rq->lock LOCK p->pi_state
++ * smp_mb__after_spinlock() smp_mb__after_spinlock()
++ * if (signal_pending_state()) if (p->state & @state)
++ *
++ * Also, the membarrier system call requires a full memory barrier
++ * after coming from user-space, before storing to rq->curr.
++ */
++ raw_spin_lock(&rq->lock);
++ smp_mb__after_spinlock();
++
++ update_rq_clock(rq);
++
++ switch_count = &prev->nivcsw;
++ /*
++ * We must load prev->state once (task_struct::state is volatile), such
++ * that:
++ *
++ * - we form a control dependency vs deactivate_task() below.
++ * - ptrace_{,un}freeze_traced() can change ->state underneath us.
++ */
++ prev_state = prev->state;
++ if (!preempt && prev_state && prev_state == prev->state) {
++ if (signal_pending_state(prev_state, prev)) {
++ prev->state = TASK_RUNNING;
++ } else {
++ prev->sched_contributes_to_load =
++ (prev_state & TASK_UNINTERRUPTIBLE) &&
++ !(prev_state & TASK_NOLOAD) &&
++ !(prev->flags & PF_FROZEN);
++
++ if (prev->sched_contributes_to_load)
++ rq->nr_uninterruptible++;
++
++ /*
++ * __schedule() ttwu()
++ * prev_state = prev->state; if (p->on_rq && ...)
++ * if (prev_state) goto out;
++ * p->on_rq = 0; smp_acquire__after_ctrl_dep();
++ * p->state = TASK_WAKING
++ *
++ * Where __schedule() and ttwu() have matching control dependencies.
++ *
++ * After this, schedule() must not care about p->state any more.
++ */
++ sched_task_deactivate(prev, rq);
++ deactivate_task(prev, rq);
++
++ if (prev->in_iowait) {
++ atomic_inc(&rq->nr_iowait);
++ delayacct_blkio_start();
++ }
++ }
++ switch_count = &prev->nvcsw;
++ }
++
++ check_curr(prev, rq);
++
++ next = choose_next_task(rq, cpu, prev);
++ clear_tsk_need_resched(prev);
++ clear_preempt_need_resched();
++
++
++ if (likely(prev != next)) {
++ next->last_ran = rq->clock_task;
++ rq->last_ts_switch = rq->clock;
++
++ rq->nr_switches++;
++ /*
++ * RCU users of rcu_dereference(rq->curr) may not see
++ * changes to task_struct made by pick_next_task().
++ */
++ RCU_INIT_POINTER(rq->curr, next);
++ /*
++ * The membarrier system call requires each architecture
++ * to have a full memory barrier after updating
++ * rq->curr, before returning to user-space.
++ *
++ * Here are the schemes providing that barrier on the
++ * various architectures:
++ * - mm ? switch_mm() : mmdrop() for x86, s390, sparc, PowerPC.
++ * switch_mm() rely on membarrier_arch_switch_mm() on PowerPC.
++ * - finish_lock_switch() for weakly-ordered
++ * architectures where spin_unlock is a full barrier,
++ * - switch_to() for arm64 (weakly-ordered, spin_unlock
++ * is a RELEASE barrier),
++ */
++ ++*switch_count;
++
++ psi_sched_switch(prev, next, !task_on_rq_queued(prev));
++
++ trace_sched_switch(preempt, prev, next);
++
++ /* Also unlocks the rq: */
++ rq = context_switch(rq, prev, next);
++ } else {
++ __balance_callbacks(rq);
++ raw_spin_unlock_irq(&rq->lock);
++ }
++
++#ifdef CONFIG_SCHED_SMT
++ sg_balance_check(rq);
++#endif
++}
++
++void __noreturn do_task_dead(void)
++{
++ /* Causes final put_task_struct in finish_task_switch(): */
++ set_special_state(TASK_DEAD);
++
++ /* Tell freezer to ignore us: */
++ current->flags |= PF_NOFREEZE;
++
++ __schedule(false);
++ BUG();
++
++ /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */
++ for (;;)
++ cpu_relax();
++}
++
++static inline void sched_submit_work(struct task_struct *tsk)
++{
++ unsigned int task_flags;
++
++ if (!tsk->state)
++ return;
++
++ task_flags = tsk->flags;
++ /*
++ * If a worker went to sleep, notify and ask workqueue whether
++ * it wants to wake up a task to maintain concurrency.
++ * As this function is called inside the schedule() context,
++ * we disable preemption to avoid it calling schedule() again
++ * in the possible wakeup of a kworker and because wq_worker_sleeping()
++ * requires it.
++ */
++ if (task_flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
++ preempt_disable();
++ if (task_flags & PF_WQ_WORKER)
++ wq_worker_sleeping(tsk);
++ else
++ io_wq_worker_sleeping(tsk);
++ preempt_enable_no_resched();
++ }
++
++ if (tsk_is_pi_blocked(tsk))
++ return;
++
++ /*
++ * If we are going to sleep and we have plugged IO queued,
++ * make sure to submit it to avoid deadlocks.
++ */
++ if (blk_needs_flush_plug(tsk))
++ blk_schedule_flush_plug(tsk);
++}
++
++static void sched_update_worker(struct task_struct *tsk)
++{
++ if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
++ if (tsk->flags & PF_WQ_WORKER)
++ wq_worker_running(tsk);
++ else
++ io_wq_worker_running(tsk);
++ }
++}
++
++asmlinkage __visible void __sched schedule(void)
++{
++ struct task_struct *tsk = current;
++
++ sched_submit_work(tsk);
++ do {
++ preempt_disable();
++ __schedule(false);
++ sched_preempt_enable_no_resched();
++ } while (need_resched());
++ sched_update_worker(tsk);
++}
++EXPORT_SYMBOL(schedule);
++
++/*
++ * synchronize_rcu_tasks() makes sure that no task is stuck in preempted
++ * state (have scheduled out non-voluntarily) by making sure that all
++ * tasks have either left the run queue or have gone into user space.
++ * As idle tasks do not do either, they must not ever be preempted
++ * (schedule out non-voluntarily).
++ *
++ * schedule_idle() is similar to schedule_preempt_disable() except that it
++ * never enables preemption because it does not call sched_submit_work().
++ */
++void __sched schedule_idle(void)
++{
++ /*
++ * As this skips calling sched_submit_work(), which the idle task does
++ * regardless because that function is a nop when the task is in a
++ * TASK_RUNNING state, make sure this isn't used someplace that the
++ * current task can be in any other state. Note, idle is always in the
++ * TASK_RUNNING state.
++ */
++ WARN_ON_ONCE(current->state);
++ do {
++ __schedule(false);
++ } while (need_resched());
++}
++
++#if defined(CONFIG_CONTEXT_TRACKING) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK)
++asmlinkage __visible void __sched schedule_user(void)
++{
++ /*
++ * If we come here after a random call to set_need_resched(),
++ * or we have been woken up remotely but the IPI has not yet arrived,
++ * we haven't yet exited the RCU idle mode. Do it here manually until
++ * we find a better solution.
++ *
++ * NB: There are buggy callers of this function. Ideally we
++ * should warn if prev_state != CONTEXT_USER, but that will trigger
++ * too frequently to make sense yet.
++ */
++ enum ctx_state prev_state = exception_enter();
++ schedule();
++ exception_exit(prev_state);
++}
++#endif
++
++/**
++ * schedule_preempt_disabled - called with preemption disabled
++ *
++ * Returns with preemption disabled. Note: preempt_count must be 1
++ */
++void __sched schedule_preempt_disabled(void)
++{
++ sched_preempt_enable_no_resched();
++ schedule();
++ preempt_disable();
++}
++
++static void __sched notrace preempt_schedule_common(void)
++{
++ do {
++ /*
++ * Because the function tracer can trace preempt_count_sub()
++ * and it also uses preempt_enable/disable_notrace(), if
++ * NEED_RESCHED is set, the preempt_enable_notrace() called
++ * by the function tracer will call this function again and
++ * cause infinite recursion.
++ *
++ * Preemption must be disabled here before the function
++ * tracer can trace. Break up preempt_disable() into two
++ * calls. One to disable preemption without fear of being
++ * traced. The other to still record the preemption latency,
++ * which can also be traced by the function tracer.
++ */
++ preempt_disable_notrace();
++ preempt_latency_start(1);
++ __schedule(true);
++ preempt_latency_stop(1);
++ preempt_enable_no_resched_notrace();
++
++ /*
++ * Check again in case we missed a preemption opportunity
++ * between schedule and now.
++ */
++ } while (need_resched());
++}
++
++#ifdef CONFIG_PREEMPTION
++/*
++ * This is the entry point to schedule() from in-kernel preemption
++ * off of preempt_enable.
++ */
++asmlinkage __visible void __sched notrace preempt_schedule(void)
++{
++ /*
++ * If there is a non-zero preempt_count or interrupts are disabled,
++ * we do not want to preempt the current task. Just return..
++ */
++ if (likely(!preemptible()))
++ return;
++
++ preempt_schedule_common();
++}
++NOKPROBE_SYMBOL(preempt_schedule);
++EXPORT_SYMBOL(preempt_schedule);
++
++#ifdef CONFIG_PREEMPT_DYNAMIC
++DEFINE_STATIC_CALL(preempt_schedule, __preempt_schedule_func);
++EXPORT_STATIC_CALL_TRAMP(preempt_schedule);
++#endif
++
++
++/**
++ * preempt_schedule_notrace - preempt_schedule called by tracing
++ *
++ * The tracing infrastructure uses preempt_enable_notrace to prevent
++ * recursion and tracing preempt enabling caused by the tracing
++ * infrastructure itself. But as tracing can happen in areas coming
++ * from userspace or just about to enter userspace, a preempt enable
++ * can occur before user_exit() is called. This will cause the scheduler
++ * to be called when the system is still in usermode.
++ *
++ * To prevent this, the preempt_enable_notrace will use this function
++ * instead of preempt_schedule() to exit user context if needed before
++ * calling the scheduler.
++ */
++asmlinkage __visible void __sched notrace preempt_schedule_notrace(void)
++{
++ enum ctx_state prev_ctx;
++
++ if (likely(!preemptible()))
++ return;
++
++ do {
++ /*
++ * Because the function tracer can trace preempt_count_sub()
++ * and it also uses preempt_enable/disable_notrace(), if
++ * NEED_RESCHED is set, the preempt_enable_notrace() called
++ * by the function tracer will call this function again and
++ * cause infinite recursion.
++ *
++ * Preemption must be disabled here before the function
++ * tracer can trace. Break up preempt_disable() into two
++ * calls. One to disable preemption without fear of being
++ * traced. The other to still record the preemption latency,
++ * which can also be traced by the function tracer.
++ */
++ preempt_disable_notrace();
++ preempt_latency_start(1);
++ /*
++ * Needs preempt disabled in case user_exit() is traced
++ * and the tracer calls preempt_enable_notrace() causing
++ * an infinite recursion.
++ */
++ prev_ctx = exception_enter();
++ __schedule(true);
++ exception_exit(prev_ctx);
++
++ preempt_latency_stop(1);
++ preempt_enable_no_resched_notrace();
++ } while (need_resched());
++}
++EXPORT_SYMBOL_GPL(preempt_schedule_notrace);
++
++#ifdef CONFIG_PREEMPT_DYNAMIC
++DEFINE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func);
++EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace);
++#endif
++
++#endif /* CONFIG_PREEMPTION */
++
++#ifdef CONFIG_PREEMPT_DYNAMIC
++
++#include <linux/entry-common.h>
++
++/*
++ * SC:cond_resched
++ * SC:might_resched
++ * SC:preempt_schedule
++ * SC:preempt_schedule_notrace
++ * SC:irqentry_exit_cond_resched
++ *
++ *
++ * NONE:
++ * cond_resched <- __cond_resched
++ * might_resched <- RET0
++ * preempt_schedule <- NOP
++ * preempt_schedule_notrace <- NOP
++ * irqentry_exit_cond_resched <- NOP
++ *
++ * VOLUNTARY:
++ * cond_resched <- __cond_resched
++ * might_resched <- __cond_resched
++ * preempt_schedule <- NOP
++ * preempt_schedule_notrace <- NOP
++ * irqentry_exit_cond_resched <- NOP
++ *
++ * FULL:
++ * cond_resched <- RET0
++ * might_resched <- RET0
++ * preempt_schedule <- preempt_schedule
++ * preempt_schedule_notrace <- preempt_schedule_notrace
++ * irqentry_exit_cond_resched <- irqentry_exit_cond_resched
++ */
++
++enum {
++ preempt_dynamic_none = 0,
++ preempt_dynamic_voluntary,
++ preempt_dynamic_full,
++};
++
++static int preempt_dynamic_mode = preempt_dynamic_full;
++
++static int sched_dynamic_mode(const char *str)
++{
++ if (!strcmp(str, "none"))
++ return 0;
++
++ if (!strcmp(str, "voluntary"))
++ return 1;
++
++ if (!strcmp(str, "full"))
++ return 2;
++
++ return -1;
++}
++
++static void sched_dynamic_update(int mode)
++{
++ /*
++ * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in
++ * the ZERO state, which is invalid.
++ */
++ static_call_update(cond_resched, __cond_resched);
++ static_call_update(might_resched, __cond_resched);
++ static_call_update(preempt_schedule, __preempt_schedule_func);
++ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func);
++ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched);
++
++ switch (mode) {
++ case preempt_dynamic_none:
++ static_call_update(cond_resched, __cond_resched);
++ static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0);
++ static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL);
++ static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL);
++ static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL);
++ pr_info("Dynamic Preempt: none\n");
++ break;
++
++ case preempt_dynamic_voluntary:
++ static_call_update(cond_resched, __cond_resched);
++ static_call_update(might_resched, __cond_resched);
++ static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL);
++ static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL);
++ static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL);
++ pr_info("Dynamic Preempt: voluntary\n");
++ break;
++
++ case preempt_dynamic_full:
++ static_call_update(cond_resched, (typeof(&__cond_resched)) __static_call_return0);
++ static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0);
++ static_call_update(preempt_schedule, __preempt_schedule_func);
++ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func);
++ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched);
++ pr_info("Dynamic Preempt: full\n");
++ break;
++ }
++
++ preempt_dynamic_mode = mode;
++}
++
++static int __init setup_preempt_mode(char *str)
++{
++ int mode = sched_dynamic_mode(str);
++ if (mode < 0) {
++ pr_warn("Dynamic Preempt: unsupported mode: %s\n", str);
++ return 1;
++ }
++
++ sched_dynamic_update(mode);
++ return 0;
++}
++__setup("preempt=", setup_preempt_mode);
++
++#ifdef CONFIG_SCHED_DEBUG
++
++static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf,
++ size_t cnt, loff_t *ppos)
++{
++ char buf[16];
++ int mode;
++
++ if (cnt > 15)
++ cnt = 15;
++
++ if (copy_from_user(&buf, ubuf, cnt))
++ return -EFAULT;
++
++ buf[cnt] = 0;
++ mode = sched_dynamic_mode(strstrip(buf));
++ if (mode < 0)
++ return mode;
++
++ sched_dynamic_update(mode);
++
++ *ppos += cnt;
++
++ return cnt;
++}
++
++static int sched_dynamic_show(struct seq_file *m, void *v)
++{
++ static const char * preempt_modes[] = {
++ "none", "voluntary", "full"
++ };
++ int i;
++
++ for (i = 0; i < ARRAY_SIZE(preempt_modes); i++) {
++ if (preempt_dynamic_mode == i)
++ seq_puts(m, "(");
++ seq_puts(m, preempt_modes[i]);
++ if (preempt_dynamic_mode == i)
++ seq_puts(m, ")");
++
++ seq_puts(m, " ");
++ }
++
++ seq_puts(m, "\n");
++ return 0;
++}
++
++static int sched_dynamic_open(struct inode *inode, struct file *filp)
++{
++ return single_open(filp, sched_dynamic_show, NULL);
++}
++
++static const struct file_operations sched_dynamic_fops = {
++ .open = sched_dynamic_open,
++ .write = sched_dynamic_write,
++ .read = seq_read,
++ .llseek = seq_lseek,
++ .release = single_release,
++};
++
++static __init int sched_init_debug_dynamic(void)
++{
++ debugfs_create_file("sched_preempt", 0644, NULL, NULL, &sched_dynamic_fops);
++ return 0;
++}
++late_initcall(sched_init_debug_dynamic);
++
++#endif /* CONFIG_SCHED_DEBUG */
++#endif /* CONFIG_PREEMPT_DYNAMIC */
++
++
++/*
++ * This is the entry point to schedule() from kernel preemption
++ * off of irq context.
++ * Note, that this is called and return with irqs disabled. This will
++ * protect us against recursive calling from irq.
++ */
++asmlinkage __visible void __sched preempt_schedule_irq(void)
++{
++ enum ctx_state prev_state;
++
++ /* Catch callers which need to be fixed */
++ BUG_ON(preempt_count() || !irqs_disabled());
++
++ prev_state = exception_enter();
++
++ do {
++ preempt_disable();
++ local_irq_enable();
++ __schedule(true);
++ local_irq_disable();
++ sched_preempt_enable_no_resched();
++ } while (need_resched());
++
++ exception_exit(prev_state);
++}
++
++int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags,
++ void *key)
++{
++ WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~WF_SYNC);
++ return try_to_wake_up(curr->private, mode, wake_flags);
++}
++EXPORT_SYMBOL(default_wake_function);
++
++static inline void check_task_changed(struct rq *rq, struct task_struct *p)
++{
++ /* Trigger resched if task sched_prio has been modified. */
++ if (task_on_rq_queued(p) && sched_task_need_requeue(p, rq)) {
++ requeue_task(p, rq);
++ check_preempt_curr(rq);
++ }
++}
++
++#ifdef CONFIG_RT_MUTEXES
++
++static inline int __rt_effective_prio(struct task_struct *pi_task, int prio)
++{
++ if (pi_task)
++ prio = min(prio, pi_task->prio);
++
++ return prio;
++}
++
++static inline int rt_effective_prio(struct task_struct *p, int prio)
++{
++ struct task_struct *pi_task = rt_mutex_get_top_task(p);
++
++ return __rt_effective_prio(pi_task, prio);
++}
++
++/*
++ * rt_mutex_setprio - set the current priority of a task
++ * @p: task to boost
++ * @pi_task: donor task
++ *
++ * This function changes the 'effective' priority of a task. It does
++ * not touch ->normal_prio like __setscheduler().
++ *
++ * Used by the rt_mutex code to implement priority inheritance
++ * logic. Call site only calls if the priority of the task changed.
++ */
++void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task)
++{
++ int prio;
++ struct rq *rq;
++ raw_spinlock_t *lock;
++
++ /* XXX used to be waiter->prio, not waiter->task->prio */
++ prio = __rt_effective_prio(pi_task, p->normal_prio);
++
++ /*
++ * If nothing changed; bail early.
++ */
++ if (p->pi_top_task == pi_task && prio == p->prio)
++ return;
++
++ rq = __task_access_lock(p, &lock);
++ /*
++ * Set under pi_lock && rq->lock, such that the value can be used under
++ * either lock.
++ *
++ * Note that there is loads of tricky to make this pointer cache work
++ * right. rt_mutex_slowunlock()+rt_mutex_postunlock() work together to
++ * ensure a task is de-boosted (pi_task is set to NULL) before the
++ * task is allowed to run again (and can exit). This ensures the pointer
++ * points to a blocked task -- which guarantees the task is present.
++ */
++ p->pi_top_task = pi_task;
++
++ /*
++ * For FIFO/RR we only need to set prio, if that matches we're done.
++ */
++ if (prio == p->prio)
++ goto out_unlock;
++
++ /*
++ * Idle task boosting is a nono in general. There is one
++ * exception, when PREEMPT_RT and NOHZ is active:
++ *
++ * The idle task calls get_next_timer_interrupt() and holds
++ * the timer wheel base->lock on the CPU and another CPU wants
++ * to access the timer (probably to cancel it). We can safely
++ * ignore the boosting request, as the idle CPU runs this code
++ * with interrupts disabled and will complete the lock
++ * protected section without being interrupted. So there is no
++ * real need to boost.
++ */
++ if (unlikely(p == rq->idle)) {
++ WARN_ON(p != rq->curr);
++ WARN_ON(p->pi_blocked_on);
++ goto out_unlock;
++ }
++
++ trace_sched_pi_setprio(p, pi_task);
++ p->prio = prio;
++ update_task_priodl(p);
++
++ check_task_changed(rq, p);
++out_unlock:
++ /* Avoid rq from going away on us: */
++ preempt_disable();
++
++ __balance_callbacks(rq);
++ __task_access_unlock(p, lock);
++
++ preempt_enable();
++}
++#else
++static inline int rt_effective_prio(struct task_struct *p, int prio)
++{
++ return prio;
++}
++#endif
++
++void set_user_nice(struct task_struct *p, long nice)
++{
++ unsigned long flags;
++ struct rq *rq;
++ raw_spinlock_t *lock;
++
++ if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE)
++ return;
++ /*
++ * We have to be careful, if called from sys_setpriority(),
++ * the task might be in the middle of scheduling on another CPU.
++ */
++ raw_spin_lock_irqsave(&p->pi_lock, flags);
++ rq = __task_access_lock(p, &lock);
++
++ p->static_prio = NICE_TO_PRIO(nice);
++ /*
++ * The RT priorities are set via sched_setscheduler(), but we still
++ * allow the 'normal' nice value to be set - but as expected
++ * it won't have any effect on scheduling until the task is
++ * not SCHED_NORMAL/SCHED_BATCH:
++ */
++ if (task_has_rt_policy(p))
++ goto out_unlock;
++
++ p->prio = effective_prio(p);
++ update_task_priodl(p);
++
++ check_task_changed(rq, p);
++out_unlock:
++ __task_access_unlock(p, lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++}
++EXPORT_SYMBOL(set_user_nice);
++
++/*
++ * can_nice - check if a task can reduce its nice value
++ * @p: task
++ * @nice: nice value
++ */
++int can_nice(const struct task_struct *p, const int nice)
++{
++ /* Convert nice value [19,-20] to rlimit style value [1,40] */
++ int nice_rlim = nice_to_rlimit(nice);
++
++ return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
++ capable(CAP_SYS_NICE));
++}
++
++#ifdef __ARCH_WANT_SYS_NICE
++
++/*
++ * sys_nice - change the priority of the current process.
++ * @increment: priority increment
++ *
++ * sys_setpriority is a more generic, but much slower function that
++ * does similar things.
++ */
++SYSCALL_DEFINE1(nice, int, increment)
++{
++ long nice, retval;
++
++ /*
++ * Setpriority might change our priority at the same moment.
++ * We don't have to worry. Conceptually one call occurs first
++ * and we have a single winner.
++ */
++
++ increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH);
++ nice = task_nice(current) + increment;
++
++ nice = clamp_val(nice, MIN_NICE, MAX_NICE);
++ if (increment < 0 && !can_nice(current, nice))
++ return -EPERM;
++
++ retval = security_task_setnice(current, nice);
++ if (retval)
++ return retval;
++
++ set_user_nice(current, nice);
++ return 0;
++}
++
++#endif
++
++/**
++ * idle_cpu - is a given CPU idle currently?
++ * @cpu: the processor in question.
++ *
++ * Return: 1 if the CPU is currently idle. 0 otherwise.
++ */
++int idle_cpu(int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++
++ if (rq->curr != rq->idle)
++ return 0;
++
++ if (rq->nr_running)
++ return 0;
++
++#ifdef CONFIG_SMP
++ if (rq->ttwu_pending)
++ return 0;
++#endif
++
++ return 1;
++}
++
++/**
++ * idle_task - return the idle task for a given CPU.
++ * @cpu: the processor in question.
++ *
++ * Return: The idle task for the cpu @cpu.
++ */
++struct task_struct *idle_task(int cpu)
++{
++ return cpu_rq(cpu)->idle;
++}
++
++/**
++ * find_process_by_pid - find a process with a matching PID value.
++ * @pid: the pid in question.
++ *
++ * The task of @pid, if found. %NULL otherwise.
++ */
++static inline struct task_struct *find_process_by_pid(pid_t pid)
++{
++ return pid ? find_task_by_vpid(pid) : current;
++}
++
++/*
++ * sched_setparam() passes in -1 for its policy, to let the functions
++ * it calls know not to change it.
++ */
++#define SETPARAM_POLICY -1
++
++static void __setscheduler_params(struct task_struct *p,
++ const struct sched_attr *attr)
++{
++ int policy = attr->sched_policy;
++
++ if (policy == SETPARAM_POLICY)
++ policy = p->policy;
++
++ p->policy = policy;
++
++ /*
++ * allow normal nice value to be set, but will not have any
++ * effect on scheduling until the task not SCHED_NORMAL/
++ * SCHED_BATCH
++ */
++ p->static_prio = NICE_TO_PRIO(attr->sched_nice);
++
++ /*
++ * __sched_setscheduler() ensures attr->sched_priority == 0 when
++ * !rt_policy. Always setting this ensures that things like
++ * getparam()/getattr() don't report silly values for !rt tasks.
++ */
++ p->rt_priority = attr->sched_priority;
++ p->normal_prio = normal_prio(p);
++}
++
++/* Actually do priority change: must hold rq lock. */
++static void __setscheduler(struct rq *rq, struct task_struct *p,
++ const struct sched_attr *attr, bool keep_boost)
++{
++ __setscheduler_params(p, attr);
++
++ /*
++ * Keep a potential priority boosting if called from
++ * sched_setscheduler().
++ */
++ p->prio = normal_prio(p);
++ if (keep_boost)
++ p->prio = rt_effective_prio(p, p->prio);
++ update_task_priodl(p);
++}
++
++/*
++ * check the target process has a UID that matches the current process's
++ */
++static bool check_same_owner(struct task_struct *p)
++{
++ const struct cred *cred = current_cred(), *pcred;
++ bool match;
++
++ rcu_read_lock();
++ pcred = __task_cred(p);
++ match = (uid_eq(cred->euid, pcred->euid) ||
++ uid_eq(cred->euid, pcred->uid));
++ rcu_read_unlock();
++ return match;
++}
++
++static int __sched_setscheduler(struct task_struct *p,
++ const struct sched_attr *attr,
++ bool user, bool pi)
++{
++ const struct sched_attr dl_squash_attr = {
++ .size = sizeof(struct sched_attr),
++ .sched_policy = SCHED_FIFO,
++ .sched_nice = 0,
++ .sched_priority = 99,
++ };
++ int newprio = MAX_RT_PRIO - 1 - attr->sched_priority;
++ int retval, oldpolicy = -1;
++ int policy = attr->sched_policy;
++ struct callback_head *head;
++ unsigned long flags;
++ struct rq *rq;
++ int reset_on_fork;
++ raw_spinlock_t *lock;
++
++ /* The pi code expects interrupts enabled */
++ BUG_ON(pi && in_interrupt());
++
++ /*
++ * Alt schedule FW supports SCHED_DEADLINE by squash it as prio 0 SCHED_FIFO
++ */
++ if (unlikely(SCHED_DEADLINE == policy)) {
++ attr = &dl_squash_attr;
++ policy = attr->sched_policy;
++ newprio = MAX_RT_PRIO - 1 - attr->sched_priority;
++ }
++recheck:
++ /* Double check policy once rq lock held */
++ if (policy < 0) {
++ reset_on_fork = p->sched_reset_on_fork;
++ policy = oldpolicy = p->policy;
++ } else {
++ reset_on_fork = !!(attr->sched_flags & SCHED_RESET_ON_FORK);
++
++ if (policy > SCHED_IDLE)
++ return -EINVAL;
++ }
++
++ if (attr->sched_flags & ~(SCHED_FLAG_ALL))
++ return -EINVAL;
++
++ /*
++ * Valid priorities for SCHED_FIFO and SCHED_RR are
++ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL and
++ * SCHED_BATCH and SCHED_IDLE is 0.
++ */
++ if (attr->sched_priority < 0 ||
++ (p->mm && attr->sched_priority > MAX_RT_PRIO - 1) ||
++ (!p->mm && attr->sched_priority > MAX_RT_PRIO - 1))
++ return -EINVAL;
++ if ((SCHED_RR == policy || SCHED_FIFO == policy) !=
++ (attr->sched_priority != 0))
++ return -EINVAL;
++
++ /*
++ * Allow unprivileged RT tasks to decrease priority:
++ */
++ if (user && !capable(CAP_SYS_NICE)) {
++ if (SCHED_FIFO == policy || SCHED_RR == policy) {
++ unsigned long rlim_rtprio =
++ task_rlimit(p, RLIMIT_RTPRIO);
++
++ /* Can't set/change the rt policy */
++ if (policy != p->policy && !rlim_rtprio)
++ return -EPERM;
++
++ /* Can't increase priority */
++ if (attr->sched_priority > p->rt_priority &&
++ attr->sched_priority > rlim_rtprio)
++ return -EPERM;
++ }
++
++ /* Can't change other user's priorities */
++ if (!check_same_owner(p))
++ return -EPERM;
++
++ /* Normal users shall not reset the sched_reset_on_fork flag */
++ if (p->sched_reset_on_fork && !reset_on_fork)
++ return -EPERM;
++ }
++
++ if (user) {
++ retval = security_task_setscheduler(p);
++ if (retval)
++ return retval;
++ }
++
++ if (pi)
++ cpuset_read_lock();
++
++ /*
++ * Make sure no PI-waiters arrive (or leave) while we are
++ * changing the priority of the task:
++ */
++ raw_spin_lock_irqsave(&p->pi_lock, flags);
++
++ /*
++ * To be able to change p->policy safely, task_access_lock()
++ * must be called.
++ * IF use task_access_lock() here:
++ * For the task p which is not running, reading rq->stop is
++ * racy but acceptable as ->stop doesn't change much.
++ * An enhancemnet can be made to read rq->stop saftly.
++ */
++ rq = __task_access_lock(p, &lock);
++
++ /*
++ * Changing the policy of the stop threads its a very bad idea
++ */
++ if (p == rq->stop) {
++ retval = -EINVAL;
++ goto unlock;
++ }
++
++ /*
++ * If not changing anything there's no need to proceed further:
++ */
++ if (unlikely(policy == p->policy)) {
++ if (rt_policy(policy) && attr->sched_priority != p->rt_priority)
++ goto change;
++ if (!rt_policy(policy) &&
++ NICE_TO_PRIO(attr->sched_nice) != p->static_prio)
++ goto change;
++
++ p->sched_reset_on_fork = reset_on_fork;
++ retval = 0;
++ goto unlock;
++ }
++change:
++
++ /* Re-check policy now with rq lock held */
++ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
++ policy = oldpolicy = -1;
++ __task_access_unlock(p, lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++ if (pi)
++ cpuset_read_unlock();
++ goto recheck;
++ }
++
++ p->sched_reset_on_fork = reset_on_fork;
++
++ if (pi) {
++ /*
++ * Take priority boosted tasks into account. If the new
++ * effective priority is unchanged, we just store the new
++ * normal parameters and do not touch the scheduler class and
++ * the runqueue. This will be done when the task deboost
++ * itself.
++ */
++ if (rt_effective_prio(p, newprio) == p->prio) {
++ __setscheduler_params(p, attr);
++ retval = 0;
++ goto unlock;
++ }
++ }
++
++ __setscheduler(rq, p, attr, pi);
++
++ check_task_changed(rq, p);
++
++ /* Avoid rq from going away on us: */
++ preempt_disable();
++ head = splice_balance_callbacks(rq);
++ __task_access_unlock(p, lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++
++ if (pi) {
++ cpuset_read_unlock();
++ rt_mutex_adjust_pi(p);
++ }
++
++ /* Run balance callbacks after we've adjusted the PI chain: */
++ balance_callbacks(rq, head);
++ preempt_enable();
++
++ return 0;
++
++unlock:
++ __task_access_unlock(p, lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, flags);
++ if (pi)
++ cpuset_read_unlock();
++ return retval;
++}
++
++static int _sched_setscheduler(struct task_struct *p, int policy,
++ const struct sched_param *param, bool check)
++{
++ struct sched_attr attr = {
++ .sched_policy = policy,
++ .sched_priority = param->sched_priority,
++ .sched_nice = PRIO_TO_NICE(p->static_prio),
++ };
++
++ /* Fixup the legacy SCHED_RESET_ON_FORK hack. */
++ if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) {
++ attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK;
++ policy &= ~SCHED_RESET_ON_FORK;
++ attr.sched_policy = policy;
++ }
++
++ return __sched_setscheduler(p, &attr, check, true);
++}
++
++/**
++ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
++ * @p: the task in question.
++ * @policy: new policy.
++ * @param: structure containing the new RT priority.
++ *
++ * Use sched_set_fifo(), read its comment.
++ *
++ * Return: 0 on success. An error code otherwise.
++ *
++ * NOTE that the task may be already dead.
++ */
++int sched_setscheduler(struct task_struct *p, int policy,
++ const struct sched_param *param)
++{
++ return _sched_setscheduler(p, policy, param, true);
++}
++
++int sched_setattr(struct task_struct *p, const struct sched_attr *attr)
++{
++ return __sched_setscheduler(p, attr, true, true);
++}
++
++int sched_setattr_nocheck(struct task_struct *p, const struct sched_attr *attr)
++{
++ return __sched_setscheduler(p, attr, false, true);
++}
++
++/**
++ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
++ * @p: the task in question.
++ * @policy: new policy.
++ * @param: structure containing the new RT priority.
++ *
++ * Just like sched_setscheduler, only don't bother checking if the
++ * current context has permission. For example, this is needed in
++ * stop_machine(): we create temporary high priority worker threads,
++ * but our caller might not have that capability.
++ *
++ * Return: 0 on success. An error code otherwise.
++ */
++int sched_setscheduler_nocheck(struct task_struct *p, int policy,
++ const struct sched_param *param)
++{
++ return _sched_setscheduler(p, policy, param, false);
++}
++
++/*
++ * SCHED_FIFO is a broken scheduler model; that is, it is fundamentally
++ * incapable of resource management, which is the one thing an OS really should
++ * be doing.
++ *
++ * This is of course the reason it is limited to privileged users only.
++ *
++ * Worse still; it is fundamentally impossible to compose static priority
++ * workloads. You cannot take two correctly working static prio workloads
++ * and smash them together and still expect them to work.
++ *
++ * For this reason 'all' FIFO tasks the kernel creates are basically at:
++ *
++ * MAX_RT_PRIO / 2
++ *
++ * The administrator _MUST_ configure the system, the kernel simply doesn't
++ * know enough information to make a sensible choice.
++ */
++void sched_set_fifo(struct task_struct *p)
++{
++ struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 };
++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0);
++}
++EXPORT_SYMBOL_GPL(sched_set_fifo);
++
++/*
++ * For when you don't much care about FIFO, but want to be above SCHED_NORMAL.
++ */
++void sched_set_fifo_low(struct task_struct *p)
++{
++ struct sched_param sp = { .sched_priority = 1 };
++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0);
++}
++EXPORT_SYMBOL_GPL(sched_set_fifo_low);
++
++void sched_set_normal(struct task_struct *p, int nice)
++{
++ struct sched_attr attr = {
++ .sched_policy = SCHED_NORMAL,
++ .sched_nice = nice,
++ };
++ WARN_ON_ONCE(sched_setattr_nocheck(p, &attr) != 0);
++}
++EXPORT_SYMBOL_GPL(sched_set_normal);
++
++static int
++do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
++{
++ struct sched_param lparam;
++ struct task_struct *p;
++ int retval;
++
++ if (!param || pid < 0)
++ return -EINVAL;
++ if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
++ return -EFAULT;
++
++ rcu_read_lock();
++ retval = -ESRCH;
++ p = find_process_by_pid(pid);
++ if (likely(p))
++ get_task_struct(p);
++ rcu_read_unlock();
++
++ if (likely(p)) {
++ retval = sched_setscheduler(p, policy, &lparam);
++ put_task_struct(p);
++ }
++
++ return retval;
++}
++
++/*
++ * Mimics kernel/events/core.c perf_copy_attr().
++ */
++static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *attr)
++{
++ u32 size;
++ int ret;
++
++ /* Zero the full structure, so that a short copy will be nice: */
++ memset(attr, 0, sizeof(*attr));
++
++ ret = get_user(size, &uattr->size);
++ if (ret)
++ return ret;
++
++ /* ABI compatibility quirk: */
++ if (!size)
++ size = SCHED_ATTR_SIZE_VER0;
++
++ if (size < SCHED_ATTR_SIZE_VER0 || size > PAGE_SIZE)
++ goto err_size;
++
++ ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size);
++ if (ret) {
++ if (ret == -E2BIG)
++ goto err_size;
++ return ret;
++ }
++
++ /*
++ * XXX: Do we want to be lenient like existing syscalls; or do we want
++ * to be strict and return an error on out-of-bounds values?
++ */
++ attr->sched_nice = clamp(attr->sched_nice, -20, 19);
++
++ /* sched/core.c uses zero here but we already know ret is zero */
++ return 0;
++
++err_size:
++ put_user(sizeof(*attr), &uattr->size);
++ return -E2BIG;
++}
++
++/**
++ * sys_sched_setscheduler - set/change the scheduler policy and RT priority
++ * @pid: the pid in question.
++ * @policy: new policy.
++ *
++ * Return: 0 on success. An error code otherwise.
++ * @param: structure containing the new RT priority.
++ */
++SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, struct sched_param __user *, param)
++{
++ if (policy < 0)
++ return -EINVAL;
++
++ return do_sched_setscheduler(pid, policy, param);
++}
++
++/**
++ * sys_sched_setparam - set/change the RT priority of a thread
++ * @pid: the pid in question.
++ * @param: structure containing the new RT priority.
++ *
++ * Return: 0 on success. An error code otherwise.
++ */
++SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
++{
++ return do_sched_setscheduler(pid, SETPARAM_POLICY, param);
++}
++
++/**
++ * sys_sched_setattr - same as above, but with extended sched_attr
++ * @pid: the pid in question.
++ * @uattr: structure containing the extended parameters.
++ */
++SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr,
++ unsigned int, flags)
++{
++ struct sched_attr attr;
++ struct task_struct *p;
++ int retval;
++
++ if (!uattr || pid < 0 || flags)
++ return -EINVAL;
++
++ retval = sched_copy_attr(uattr, &attr);
++ if (retval)
++ return retval;
++
++ if ((int)attr.sched_policy < 0)
++ return -EINVAL;
++
++ rcu_read_lock();
++ retval = -ESRCH;
++ p = find_process_by_pid(pid);
++ if (likely(p))
++ get_task_struct(p);
++ rcu_read_unlock();
++
++ if (likely(p)) {
++ retval = sched_setattr(p, &attr);
++ put_task_struct(p);
++ }
++
++ return retval;
++}
++
++/**
++ * sys_sched_getscheduler - get the policy (scheduling class) of a thread
++ * @pid: the pid in question.
++ *
++ * Return: On success, the policy of the thread. Otherwise, a negative error
++ * code.
++ */
++SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
++{
++ struct task_struct *p;
++ int retval = -EINVAL;
++
++ if (pid < 0)
++ goto out_nounlock;
++
++ retval = -ESRCH;
++ rcu_read_lock();
++ p = find_process_by_pid(pid);
++ if (p) {
++ retval = security_task_getscheduler(p);
++ if (!retval)
++ retval = p->policy;
++ }
++ rcu_read_unlock();
++
++out_nounlock:
++ return retval;
++}
++
++/**
++ * sys_sched_getscheduler - get the RT priority of a thread
++ * @pid: the pid in question.
++ * @param: structure containing the RT priority.
++ *
++ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error
++ * code.
++ */
++SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
++{
++ struct sched_param lp = { .sched_priority = 0 };
++ struct task_struct *p;
++ int retval = -EINVAL;
++
++ if (!param || pid < 0)
++ goto out_nounlock;
++
++ rcu_read_lock();
++ p = find_process_by_pid(pid);
++ retval = -ESRCH;
++ if (!p)
++ goto out_unlock;
++
++ retval = security_task_getscheduler(p);
++ if (retval)
++ goto out_unlock;
++
++ if (task_has_rt_policy(p))
++ lp.sched_priority = p->rt_priority;
++ rcu_read_unlock();
++
++ /*
++ * This one might sleep, we cannot do it with a spinlock held ...
++ */
++ retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
++
++out_nounlock:
++ return retval;
++
++out_unlock:
++ rcu_read_unlock();
++ return retval;
++}
++
++/*
++ * Copy the kernel size attribute structure (which might be larger
++ * than what user-space knows about) to user-space.
++ *
++ * Note that all cases are valid: user-space buffer can be larger or
++ * smaller than the kernel-space buffer. The usual case is that both
++ * have the same size.
++ */
++static int
++sched_attr_copy_to_user(struct sched_attr __user *uattr,
++ struct sched_attr *kattr,
++ unsigned int usize)
++{
++ unsigned int ksize = sizeof(*kattr);
++
++ if (!access_ok(uattr, usize))
++ return -EFAULT;
++
++ /*
++ * sched_getattr() ABI forwards and backwards compatibility:
++ *
++ * If usize == ksize then we just copy everything to user-space and all is good.
++ *
++ * If usize < ksize then we only copy as much as user-space has space for,
++ * this keeps ABI compatibility as well. We skip the rest.
++ *
++ * If usize > ksize then user-space is using a newer version of the ABI,
++ * which part the kernel doesn't know about. Just ignore it - tooling can
++ * detect the kernel's knowledge of attributes from the attr->size value
++ * which is set to ksize in this case.
++ */
++ kattr->size = min(usize, ksize);
++
++ if (copy_to_user(uattr, kattr, kattr->size))
++ return -EFAULT;
++
++ return 0;
++}
++
++/**
++ * sys_sched_getattr - similar to sched_getparam, but with sched_attr
++ * @pid: the pid in question.
++ * @uattr: structure containing the extended parameters.
++ * @usize: sizeof(attr) for fwd/bwd comp.
++ * @flags: for future extension.
++ */
++SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
++ unsigned int, usize, unsigned int, flags)
++{
++ struct sched_attr kattr = { };
++ struct task_struct *p;
++ int retval;
++
++ if (!uattr || pid < 0 || usize > PAGE_SIZE ||
++ usize < SCHED_ATTR_SIZE_VER0 || flags)
++ return -EINVAL;
++
++ rcu_read_lock();
++ p = find_process_by_pid(pid);
++ retval = -ESRCH;
++ if (!p)
++ goto out_unlock;
++
++ retval = security_task_getscheduler(p);
++ if (retval)
++ goto out_unlock;
++
++ kattr.sched_policy = p->policy;
++ if (p->sched_reset_on_fork)
++ kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK;
++ if (task_has_rt_policy(p))
++ kattr.sched_priority = p->rt_priority;
++ else
++ kattr.sched_nice = task_nice(p);
++
++#ifdef CONFIG_UCLAMP_TASK
++ kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value;
++ kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value;
++#endif
++
++ rcu_read_unlock();
++
++ return sched_attr_copy_to_user(uattr, &kattr, usize);
++
++out_unlock:
++ rcu_read_unlock();
++ return retval;
++}
++
++long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
++{
++ cpumask_var_t cpus_allowed, new_mask;
++ struct task_struct *p;
++ int retval;
++
++ rcu_read_lock();
++
++ p = find_process_by_pid(pid);
++ if (!p) {
++ rcu_read_unlock();
++ return -ESRCH;
++ }
++
++ /* Prevent p going away */
++ get_task_struct(p);
++ rcu_read_unlock();
++
++ if (p->flags & PF_NO_SETAFFINITY) {
++ retval = -EINVAL;
++ goto out_put_task;
++ }
++ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
++ retval = -ENOMEM;
++ goto out_put_task;
++ }
++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
++ retval = -ENOMEM;
++ goto out_free_cpus_allowed;
++ }
++ retval = -EPERM;
++ if (!check_same_owner(p)) {
++ rcu_read_lock();
++ if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
++ rcu_read_unlock();
++ goto out_free_new_mask;
++ }
++ rcu_read_unlock();
++ }
++
++ retval = security_task_setscheduler(p);
++ if (retval)
++ goto out_free_new_mask;
++
++ cpuset_cpus_allowed(p, cpus_allowed);
++ cpumask_and(new_mask, in_mask, cpus_allowed);
++
++again:
++ retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK);
++
++ if (!retval) {
++ cpuset_cpus_allowed(p, cpus_allowed);
++ if (!cpumask_subset(new_mask, cpus_allowed)) {
++ /*
++ * We must have raced with a concurrent cpuset
++ * update. Just reset the cpus_allowed to the
++ * cpuset's cpus_allowed
++ */
++ cpumask_copy(new_mask, cpus_allowed);
++ goto again;
++ }
++ }
++out_free_new_mask:
++ free_cpumask_var(new_mask);
++out_free_cpus_allowed:
++ free_cpumask_var(cpus_allowed);
++out_put_task:
++ put_task_struct(p);
++ return retval;
++}
++
++static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
++ struct cpumask *new_mask)
++{
++ if (len < cpumask_size())
++ cpumask_clear(new_mask);
++ else if (len > cpumask_size())
++ len = cpumask_size();
++
++ return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
++}
++
++/**
++ * sys_sched_setaffinity - set the CPU affinity of a process
++ * @pid: pid of the process
++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
++ * @user_mask_ptr: user-space pointer to the new CPU mask
++ *
++ * Return: 0 on success. An error code otherwise.
++ */
++SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
++ unsigned long __user *, user_mask_ptr)
++{
++ cpumask_var_t new_mask;
++ int retval;
++
++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
++ return -ENOMEM;
++
++ retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
++ if (retval == 0)
++ retval = sched_setaffinity(pid, new_mask);
++ free_cpumask_var(new_mask);
++ return retval;
++}
++
++long sched_getaffinity(pid_t pid, cpumask_t *mask)
++{
++ struct task_struct *p;
++ raw_spinlock_t *lock;
++ unsigned long flags;
++ int retval;
++
++ rcu_read_lock();
++
++ retval = -ESRCH;
++ p = find_process_by_pid(pid);
++ if (!p)
++ goto out_unlock;
++
++ retval = security_task_getscheduler(p);
++ if (retval)
++ goto out_unlock;
++
++ task_access_lock_irqsave(p, &lock, &flags);
++ cpumask_and(mask, &p->cpus_mask, cpu_active_mask);
++ task_access_unlock_irqrestore(p, lock, &flags);
++
++out_unlock:
++ rcu_read_unlock();
++
++ return retval;
++}
++
++/**
++ * sys_sched_getaffinity - get the CPU affinity of a process
++ * @pid: pid of the process
++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
++ * @user_mask_ptr: user-space pointer to hold the current CPU mask
++ *
++ * Return: size of CPU mask copied to user_mask_ptr on success. An
++ * error code otherwise.
++ */
++SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
++ unsigned long __user *, user_mask_ptr)
++{
++ int ret;
++ cpumask_var_t mask;
++
++ if ((len * BITS_PER_BYTE) < nr_cpu_ids)
++ return -EINVAL;
++ if (len & (sizeof(unsigned long)-1))
++ return -EINVAL;
++
++ if (!alloc_cpumask_var(&mask, GFP_KERNEL))
++ return -ENOMEM;
++
++ ret = sched_getaffinity(pid, mask);
++ if (ret == 0) {
++ unsigned int retlen = min_t(size_t, len, cpumask_size());
++
++ if (copy_to_user(user_mask_ptr, mask, retlen))
++ ret = -EFAULT;
++ else
++ ret = retlen;
++ }
++ free_cpumask_var(mask);
++
++ return ret;
++}
++
++static void do_sched_yield(void)
++{
++ struct rq *rq;
++ struct rq_flags rf;
++
++ if (!sched_yield_type)
++ return;
++
++ rq = this_rq_lock_irq(&rf);
++
++ schedstat_inc(rq->yld_count);
++
++ if (1 == sched_yield_type) {
++ if (!rt_task(current))
++ do_sched_yield_type_1(current, rq);
++ } else if (2 == sched_yield_type) {
++ if (rq->nr_running > 1)
++ rq->skip = current;
++ }
++
++ preempt_disable();
++ raw_spin_unlock_irq(&rq->lock);
++ sched_preempt_enable_no_resched();
++
++ schedule();
++}
++
++/**
++ * sys_sched_yield - yield the current processor to other threads.
++ *
++ * This function yields the current CPU to other tasks. If there are no
++ * other threads running on this CPU then this function will return.
++ *
++ * Return: 0.
++ */
++SYSCALL_DEFINE0(sched_yield)
++{
++ do_sched_yield();
++ return 0;
++}
++
++#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
++int __sched __cond_resched(void)
++{
++ if (should_resched(0)) {
++ preempt_schedule_common();
++ return 1;
++ }
++#ifndef CONFIG_PREEMPT_RCU
++ rcu_all_qs();
++#endif
++ return 0;
++}
++EXPORT_SYMBOL(__cond_resched);
++#endif
++
++#ifdef CONFIG_PREEMPT_DYNAMIC
++DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched);
++EXPORT_STATIC_CALL_TRAMP(cond_resched);
++
++DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched);
++EXPORT_STATIC_CALL_TRAMP(might_resched);
++#endif
++
++/*
++ * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
++ * call schedule, and on return reacquire the lock.
++ *
++ * This works OK both with and without CONFIG_PREEMPTION. We do strange low-level
++ * operations here to prevent schedule() from being called twice (once via
++ * spin_unlock(), once by hand).
++ */
++int __cond_resched_lock(spinlock_t *lock)
++{
++ int resched = should_resched(PREEMPT_LOCK_OFFSET);
++ int ret = 0;
++
++ lockdep_assert_held(lock);
++
++ if (spin_needbreak(lock) || resched) {
++ spin_unlock(lock);
++ if (resched)
++ preempt_schedule_common();
++ else
++ cpu_relax();
++ ret = 1;
++ spin_lock(lock);
++ }
++ return ret;
++}
++EXPORT_SYMBOL(__cond_resched_lock);
++
++int __cond_resched_rwlock_read(rwlock_t *lock)
++{
++ int resched = should_resched(PREEMPT_LOCK_OFFSET);
++ int ret = 0;
++
++ lockdep_assert_held_read(lock);
++
++ if (rwlock_needbreak(lock) || resched) {
++ read_unlock(lock);
++ if (resched)
++ preempt_schedule_common();
++ else
++ cpu_relax();
++ ret = 1;
++ read_lock(lock);
++ }
++ return ret;
++}
++EXPORT_SYMBOL(__cond_resched_rwlock_read);
++
++int __cond_resched_rwlock_write(rwlock_t *lock)
++{
++ int resched = should_resched(PREEMPT_LOCK_OFFSET);
++ int ret = 0;
++
++ lockdep_assert_held_write(lock);
++
++ if (rwlock_needbreak(lock) || resched) {
++ write_unlock(lock);
++ if (resched)
++ preempt_schedule_common();
++ else
++ cpu_relax();
++ ret = 1;
++ write_lock(lock);
++ }
++ return ret;
++}
++EXPORT_SYMBOL(__cond_resched_rwlock_write);
++
++/**
++ * yield - yield the current processor to other threads.
++ *
++ * Do not ever use this function, there's a 99% chance you're doing it wrong.
++ *
++ * The scheduler is at all times free to pick the calling task as the most
++ * eligible task to run, if removing the yield() call from your code breaks
++ * it, it's already broken.
++ *
++ * Typical broken usage is:
++ *
++ * while (!event)
++ * yield();
++ *
++ * where one assumes that yield() will let 'the other' process run that will
++ * make event true. If the current task is a SCHED_FIFO task that will never
++ * happen. Never use yield() as a progress guarantee!!
++ *
++ * If you want to use yield() to wait for something, use wait_event().
++ * If you want to use yield() to be 'nice' for others, use cond_resched().
++ * If you still want to use yield(), do not!
++ */
++void __sched yield(void)
++{
++ set_current_state(TASK_RUNNING);
++ do_sched_yield();
++}
++EXPORT_SYMBOL(yield);
++
++/**
++ * yield_to - yield the current processor to another thread in
++ * your thread group, or accelerate that thread toward the
++ * processor it's on.
++ * @p: target task
++ * @preempt: whether task preemption is allowed or not
++ *
++ * It's the caller's job to ensure that the target task struct
++ * can't go away on us before we can do any checks.
++ *
++ * In Alt schedule FW, yield_to is not supported.
++ *
++ * Return:
++ * true (>0) if we indeed boosted the target task.
++ * false (0) if we failed to boost the target.
++ * -ESRCH if there's no task to yield to.
++ */
++int __sched yield_to(struct task_struct *p, bool preempt)
++{
++ return 0;
++}
++EXPORT_SYMBOL_GPL(yield_to);
++
++int io_schedule_prepare(void)
++{
++ int old_iowait = current->in_iowait;
++
++ current->in_iowait = 1;
++ blk_schedule_flush_plug(current);
++
++ return old_iowait;
++}
++
++void io_schedule_finish(int token)
++{
++ current->in_iowait = token;
++}
++
++/*
++ * This task is about to go to sleep on IO. Increment rq->nr_iowait so
++ * that process accounting knows that this is a task in IO wait state.
++ *
++ * But don't do that if it is a deliberate, throttling IO wait (this task
++ * has set its backing_dev_info: the queue against which it should throttle)
++ */
++
++long __sched io_schedule_timeout(long timeout)
++{
++ int token;
++ long ret;
++
++ token = io_schedule_prepare();
++ ret = schedule_timeout(timeout);
++ io_schedule_finish(token);
++
++ return ret;
++}
++EXPORT_SYMBOL(io_schedule_timeout);
++
++void __sched io_schedule(void)
++{
++ int token;
++
++ token = io_schedule_prepare();
++ schedule();
++ io_schedule_finish(token);
++}
++EXPORT_SYMBOL(io_schedule);
++
++/**
++ * sys_sched_get_priority_max - return maximum RT priority.
++ * @policy: scheduling class.
++ *
++ * Return: On success, this syscall returns the maximum
++ * rt_priority that can be used by a given scheduling class.
++ * On failure, a negative error code is returned.
++ */
++SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
++{
++ int ret = -EINVAL;
++
++ switch (policy) {
++ case SCHED_FIFO:
++ case SCHED_RR:
++ ret = MAX_RT_PRIO - 1;
++ break;
++ case SCHED_NORMAL:
++ case SCHED_BATCH:
++ case SCHED_IDLE:
++ ret = 0;
++ break;
++ }
++ return ret;
++}
++
++/**
++ * sys_sched_get_priority_min - return minimum RT priority.
++ * @policy: scheduling class.
++ *
++ * Return: On success, this syscall returns the minimum
++ * rt_priority that can be used by a given scheduling class.
++ * On failure, a negative error code is returned.
++ */
++SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
++{
++ int ret = -EINVAL;
++
++ switch (policy) {
++ case SCHED_FIFO:
++ case SCHED_RR:
++ ret = 1;
++ break;
++ case SCHED_NORMAL:
++ case SCHED_BATCH:
++ case SCHED_IDLE:
++ ret = 0;
++ break;
++ }
++ return ret;
++}
++
++static int sched_rr_get_interval(pid_t pid, struct timespec64 *t)
++{
++ struct task_struct *p;
++ int retval;
++
++ alt_sched_debug();
++
++ if (pid < 0)
++ return -EINVAL;
++
++ retval = -ESRCH;
++ rcu_read_lock();
++ p = find_process_by_pid(pid);
++ if (!p)
++ goto out_unlock;
++
++ retval = security_task_getscheduler(p);
++ if (retval)
++ goto out_unlock;
++ rcu_read_unlock();
++
++ *t = ns_to_timespec64(sched_timeslice_ns);
++ return 0;
++
++out_unlock:
++ rcu_read_unlock();
++ return retval;
++}
++
++/**
++ * sys_sched_rr_get_interval - return the default timeslice of a process.
++ * @pid: pid of the process.
++ * @interval: userspace pointer to the timeslice value.
++ *
++ *
++ * Return: On success, 0 and the timeslice is in @interval. Otherwise,
++ * an error code.
++ */
++SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
++ struct __kernel_timespec __user *, interval)
++{
++ struct timespec64 t;
++ int retval = sched_rr_get_interval(pid, &t);
++
++ if (retval == 0)
++ retval = put_timespec64(&t, interval);
++
++ return retval;
++}
++
++#ifdef CONFIG_COMPAT_32BIT_TIME
++SYSCALL_DEFINE2(sched_rr_get_interval_time32, pid_t, pid,
++ struct old_timespec32 __user *, interval)
++{
++ struct timespec64 t;
++ int retval = sched_rr_get_interval(pid, &t);
++
++ if (retval == 0)
++ retval = put_old_timespec32(&t, interval);
++ return retval;
++}
++#endif
++
++void sched_show_task(struct task_struct *p)
++{
++ unsigned long free = 0;
++ int ppid;
++
++ if (!try_get_task_stack(p))
++ return;
++
++ pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p));
++
++ if (p->state == TASK_RUNNING)
++ pr_cont(" running task ");
++#ifdef CONFIG_DEBUG_STACK_USAGE
++ free = stack_not_used(p);
++#endif
++ ppid = 0;
++ rcu_read_lock();
++ if (pid_alive(p))
++ ppid = task_pid_nr(rcu_dereference(p->real_parent));
++ rcu_read_unlock();
++ pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n",
++ free, task_pid_nr(p), ppid,
++ (unsigned long)task_thread_info(p)->flags);
++
++ print_worker_info(KERN_INFO, p);
++ print_stop_info(KERN_INFO, p);
++ show_stack(p, NULL, KERN_INFO);
++ put_task_stack(p);
++}
++EXPORT_SYMBOL_GPL(sched_show_task);
++
++static inline bool
++state_filter_match(unsigned long state_filter, struct task_struct *p)
++{
++ /* no filter, everything matches */
++ if (!state_filter)
++ return true;
++
++ /* filter, but doesn't match */
++ if (!(p->state & state_filter))
++ return false;
++
++ /*
++ * When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows
++ * TASK_KILLABLE).
++ */
++ if (state_filter == TASK_UNINTERRUPTIBLE && p->state == TASK_IDLE)
++ return false;
++
++ return true;
++}
++
++
++void show_state_filter(unsigned long state_filter)
++{
++ struct task_struct *g, *p;
++
++ rcu_read_lock();
++ for_each_process_thread(g, p) {
++ /*
++ * reset the NMI-timeout, listing all files on a slow
++ * console might take a lot of time:
++ * Also, reset softlockup watchdogs on all CPUs, because
++ * another CPU might be blocked waiting for us to process
++ * an IPI.
++ */
++ touch_nmi_watchdog();
++ touch_all_softlockup_watchdogs();
++ if (state_filter_match(state_filter, p))
++ sched_show_task(p);
++ }
++
++#ifdef CONFIG_SCHED_DEBUG
++ /* TODO: Alt schedule FW should support this
++ if (!state_filter)
++ sysrq_sched_debug_show();
++ */
++#endif
++ rcu_read_unlock();
++ /*
++ * Only show locks if all tasks are dumped:
++ */
++ if (!state_filter)
++ debug_show_all_locks();
++}
++
++void dump_cpu_task(int cpu)
++{
++ pr_info("Task dump for CPU %d:\n", cpu);
++ sched_show_task(cpu_curr(cpu));
++}
++
++/**
++ * init_idle - set up an idle thread for a given CPU
++ * @idle: task in question
++ * @cpu: CPU the idle task belongs to
++ *
++ * NOTE: this function does not set the idle thread's NEED_RESCHED
++ * flag, to make booting more robust.
++ */
++void init_idle(struct task_struct *idle, int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++ unsigned long flags;
++
++ __sched_fork(0, idle);
++
++ raw_spin_lock_irqsave(&idle->pi_lock, flags);
++ raw_spin_lock(&rq->lock);
++ update_rq_clock(rq);
++
++ idle->last_ran = rq->clock_task;
++ idle->state = TASK_RUNNING;
++ idle->flags |= PF_IDLE;
++ sched_queue_init_idle(rq, idle);
++
++ scs_task_reset(idle);
++ kasan_unpoison_task_stack(idle);
++
++#ifdef CONFIG_SMP
++ /*
++ * It's possible that init_idle() gets called multiple times on a task,
++ * in that case do_set_cpus_allowed() will not do the right thing.
++ *
++ * And since this is boot we can forgo the serialisation.
++ */
++ set_cpus_allowed_common(idle, cpumask_of(cpu), 0);
++#endif
++
++ /* Silence PROVE_RCU */
++ rcu_read_lock();
++ __set_task_cpu(idle, cpu);
++ rcu_read_unlock();
++
++ rq->idle = idle;
++ rcu_assign_pointer(rq->curr, idle);
++ idle->on_cpu = 1;
++
++ raw_spin_unlock(&rq->lock);
++ raw_spin_unlock_irqrestore(&idle->pi_lock, flags);
++
++ /* Set the preempt count _outside_ the spinlocks! */
++ init_idle_preempt_count(idle, cpu);
++
++ ftrace_graph_init_idle_task(idle, cpu);
++ vtime_init_idle(idle, cpu);
++#ifdef CONFIG_SMP
++ sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
++#endif
++}
++
++#ifdef CONFIG_SMP
++
++int cpuset_cpumask_can_shrink(const struct cpumask __maybe_unused *cur,
++ const struct cpumask __maybe_unused *trial)
++{
++ return 1;
++}
++
++int task_can_attach(struct task_struct *p,
++ const struct cpumask *cs_cpus_allowed)
++{
++ int ret = 0;
++
++ /*
++ * Kthreads which disallow setaffinity shouldn't be moved
++ * to a new cpuset; we don't want to change their CPU
++ * affinity and isolating such threads by their set of
++ * allowed nodes is unnecessary. Thus, cpusets are not
++ * applicable for such threads. This prevents checking for
++ * success of set_cpus_allowed_ptr() on all attached tasks
++ * before cpus_mask may be changed.
++ */
++ if (p->flags & PF_NO_SETAFFINITY)
++ ret = -EINVAL;
++
++ return ret;
++}
++
++bool sched_smp_initialized __read_mostly;
++
++#ifdef CONFIG_HOTPLUG_CPU
++/*
++ * Ensures that the idle task is using init_mm right before its CPU goes
++ * offline.
++ */
++void idle_task_exit(void)
++{
++ struct mm_struct *mm = current->active_mm;
++
++ BUG_ON(current != this_rq()->idle);
++
++ if (mm != &init_mm) {
++ switch_mm(mm, &init_mm, current);
++ finish_arch_post_lock_switch();
++ }
++
++ /* finish_cpu(), as ran on the BP, will clean up the active_mm state */
++}
++
++static int __balance_push_cpu_stop(void *arg)
++{
++ struct task_struct *p = arg;
++ struct rq *rq = this_rq();
++ struct rq_flags rf;
++ int cpu;
++
++ raw_spin_lock_irq(&p->pi_lock);
++ rq_lock(rq, &rf);
++
++ update_rq_clock(rq);
++
++ if (task_rq(p) == rq && task_on_rq_queued(p)) {
++ cpu = select_fallback_rq(rq->cpu, p);
++ rq = __migrate_task(rq, p, cpu);
++ }
++
++ rq_unlock(rq, &rf);
++ raw_spin_unlock_irq(&p->pi_lock);
++
++ put_task_struct(p);
++
++ return 0;
++}
++
++static DEFINE_PER_CPU(struct cpu_stop_work, push_work);
++
++/*
++ * Ensure we only run per-cpu kthreads once the CPU goes !active.
++ */
++static void balance_push(struct rq *rq)
++{
++ struct task_struct *push_task = rq->curr;
++
++ lockdep_assert_held(&rq->lock);
++ SCHED_WARN_ON(rq->cpu != smp_processor_id());
++ /*
++ * Ensure the thing is persistent until balance_push_set(.on = false);
++ */
++ rq->balance_callback = &balance_push_callback;
++
++ /*
++ * Both the cpu-hotplug and stop task are in this case and are
++ * required to complete the hotplug process.
++ *
++ * XXX: the idle task does not match kthread_is_per_cpu() due to
++ * histerical raisins.
++ */
++ if (rq->idle == push_task ||
++ ((push_task->flags & PF_KTHREAD) && kthread_is_per_cpu(push_task)) ||
++ is_migration_disabled(push_task)) {
++
++ /*
++ * If this is the idle task on the outgoing CPU try to wake
++ * up the hotplug control thread which might wait for the
++ * last task to vanish. The rcuwait_active() check is
++ * accurate here because the waiter is pinned on this CPU
++ * and can't obviously be running in parallel.
++ *
++ * On RT kernels this also has to check whether there are
++ * pinned and scheduled out tasks on the runqueue. They
++ * need to leave the migrate disabled section first.
++ */
++ if (!rq->nr_running && !rq_has_pinned_tasks(rq) &&
++ rcuwait_active(&rq->hotplug_wait)) {
++ raw_spin_unlock(&rq->lock);
++ rcuwait_wake_up(&rq->hotplug_wait);
++ raw_spin_lock(&rq->lock);
++ }
++ return;
++ }
++
++ get_task_struct(push_task);
++ /*
++ * Temporarily drop rq->lock such that we can wake-up the stop task.
++ * Both preemption and IRQs are still disabled.
++ */
++ raw_spin_unlock(&rq->lock);
++ stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task,
++ this_cpu_ptr(&push_work));
++ /*
++ * At this point need_resched() is true and we'll take the loop in
++ * schedule(). The next pick is obviously going to be the stop task
++ * which kthread_is_per_cpu() and will push this task away.
++ */
++ raw_spin_lock(&rq->lock);
++}
++
++static void balance_push_set(int cpu, bool on)
++{
++ struct rq *rq = cpu_rq(cpu);
++ struct rq_flags rf;
++
++ rq_lock_irqsave(rq, &rf);
++ rq->balance_push = on;
++ if (on) {
++ WARN_ON_ONCE(rq->balance_callback);
++ rq->balance_callback = &balance_push_callback;
++ } else if (rq->balance_callback == &balance_push_callback) {
++ rq->balance_callback = NULL;
++ }
++ rq_unlock_irqrestore(rq, &rf);
++}
++
++/*
++ * Invoked from a CPUs hotplug control thread after the CPU has been marked
++ * inactive. All tasks which are not per CPU kernel threads are either
++ * pushed off this CPU now via balance_push() or placed on a different CPU
++ * during wakeup. Wait until the CPU is quiescent.
++ */
++static void balance_hotplug_wait(void)
++{
++ struct rq *rq = this_rq();
++
++ rcuwait_wait_event(&rq->hotplug_wait,
++ rq->nr_running == 1 && !rq_has_pinned_tasks(rq),
++ TASK_UNINTERRUPTIBLE);
++}
++
++#else
++
++static void balance_push(struct rq *rq)
++{
++}
++
++static void balance_push_set(int cpu, bool on)
++{
++}
++
++static inline void balance_hotplug_wait(void)
++{
++}
++#endif /* CONFIG_HOTPLUG_CPU */
++
++static void set_rq_offline(struct rq *rq)
++{
++ if (rq->online)
++ rq->online = false;
++}
++
++static void set_rq_online(struct rq *rq)
++{
++ if (!rq->online)
++ rq->online = true;
++}
++
++/*
++ * used to mark begin/end of suspend/resume:
++ */
++static int num_cpus_frozen;
++
++/*
++ * Update cpusets according to cpu_active mask. If cpusets are
++ * disabled, cpuset_update_active_cpus() becomes a simple wrapper
++ * around partition_sched_domains().
++ *
++ * If we come here as part of a suspend/resume, don't touch cpusets because we
++ * want to restore it back to its original state upon resume anyway.
++ */
++static void cpuset_cpu_active(void)
++{
++ if (cpuhp_tasks_frozen) {
++ /*
++ * num_cpus_frozen tracks how many CPUs are involved in suspend
++ * resume sequence. As long as this is not the last online
++ * operation in the resume sequence, just build a single sched
++ * domain, ignoring cpusets.
++ */
++ partition_sched_domains(1, NULL, NULL);
++ if (--num_cpus_frozen)
++ return;
++ /*
++ * This is the last CPU online operation. So fall through and
++ * restore the original sched domains by considering the
++ * cpuset configurations.
++ */
++ cpuset_force_rebuild();
++ }
++
++ cpuset_update_active_cpus();
++}
++
++static int cpuset_cpu_inactive(unsigned int cpu)
++{
++ if (!cpuhp_tasks_frozen) {
++ cpuset_update_active_cpus();
++ } else {
++ num_cpus_frozen++;
++ partition_sched_domains(1, NULL, NULL);
++ }
++ return 0;
++}
++
++int sched_cpu_activate(unsigned int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++ unsigned long flags;
++
++ /*
++ * Make sure that when the hotplug state machine does a roll-back
++ * we clear balance_push. Ideally that would happen earlier...
++ */
++ balance_push_set(cpu, false);
++
++#ifdef CONFIG_SCHED_SMT
++ /*
++ * When going up, increment the number of cores with SMT present.
++ */
++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2)
++ static_branch_inc_cpuslocked(&sched_smt_present);
++#endif
++ set_cpu_active(cpu, true);
++
++ if (sched_smp_initialized)
++ cpuset_cpu_active();
++
++ /*
++ * Put the rq online, if not already. This happens:
++ *
++ * 1) In the early boot process, because we build the real domains
++ * after all cpus have been brought up.
++ *
++ * 2) At runtime, if cpuset_cpu_active() fails to rebuild the
++ * domains.
++ */
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ set_rq_online(rq);
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++
++ return 0;
++}
++
++int sched_cpu_deactivate(unsigned int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++ unsigned long flags;
++ int ret;
++
++ set_cpu_active(cpu, false);
++
++ /*
++ * From this point forward, this CPU will refuse to run any task that
++ * is not: migrate_disable() or KTHREAD_IS_PER_CPU, and will actively
++ * push those tasks away until this gets cleared, see
++ * sched_cpu_dying().
++ */
++ balance_push_set(cpu, true);
++
++ /*
++ * We've cleared cpu_active_mask, wait for all preempt-disabled and RCU
++ * users of this state to go away such that all new such users will
++ * observe it.
++ *
++ * Specifically, we rely on ttwu to no longer target this CPU, see
++ * ttwu_queue_cond() and is_cpu_allowed().
++ *
++ * Do sync before park smpboot threads to take care the rcu boost case.
++ */
++ synchronize_rcu();
++
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ update_rq_clock(rq);
++ set_rq_offline(rq);
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++
++#ifdef CONFIG_SCHED_SMT
++ /*
++ * When going down, decrement the number of cores with SMT present.
++ */
++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) {
++ static_branch_dec_cpuslocked(&sched_smt_present);
++ if (!static_branch_likely(&sched_smt_present))
++ cpumask_clear(&sched_sg_idle_mask);
++ }
++#endif
++
++ if (!sched_smp_initialized)
++ return 0;
++
++ ret = cpuset_cpu_inactive(cpu);
++ if (ret) {
++ balance_push_set(cpu, false);
++ set_cpu_active(cpu, true);
++ return ret;
++ }
++
++ return 0;
++}
++
++static void sched_rq_cpu_starting(unsigned int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++
++ rq->calc_load_update = calc_load_update;
++}
++
++int sched_cpu_starting(unsigned int cpu)
++{
++ sched_rq_cpu_starting(cpu);
++ sched_tick_start(cpu);
++ return 0;
++}
++
++#ifdef CONFIG_HOTPLUG_CPU
++
++/*
++ * Invoked immediately before the stopper thread is invoked to bring the
++ * CPU down completely. At this point all per CPU kthreads except the
++ * hotplug thread (current) and the stopper thread (inactive) have been
++ * either parked or have been unbound from the outgoing CPU. Ensure that
++ * any of those which might be on the way out are gone.
++ *
++ * If after this point a bound task is being woken on this CPU then the
++ * responsible hotplug callback has failed to do it's job.
++ * sched_cpu_dying() will catch it with the appropriate fireworks.
++ */
++int sched_cpu_wait_empty(unsigned int cpu)
++{
++ balance_hotplug_wait();
++ return 0;
++}
++
++/*
++ * Since this CPU is going 'away' for a while, fold any nr_active delta we
++ * might have. Called from the CPU stopper task after ensuring that the
++ * stopper is the last running task on the CPU, so nr_active count is
++ * stable. We need to take the teardown thread which is calling this into
++ * account, so we hand in adjust = 1 to the load calculation.
++ *
++ * Also see the comment "Global load-average calculations".
++ */
++static void calc_load_migrate(struct rq *rq)
++{
++ long delta = calc_load_fold_active(rq, 1);
++
++ if (delta)
++ atomic_long_add(delta, &calc_load_tasks);
++}
++
++static void dump_rq_tasks(struct rq *rq, const char *loglvl)
++{
++ struct task_struct *g, *p;
++ int cpu = cpu_of(rq);
++
++ lockdep_assert_held(&rq->lock);
++
++ printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running);
++ for_each_process_thread(g, p) {
++ if (task_cpu(p) != cpu)
++ continue;
++
++ if (!task_on_rq_queued(p))
++ continue;
++
++ printk("%s\tpid: %d, name: %s\n", loglvl, p->pid, p->comm);
++ }
++}
++
++int sched_cpu_dying(unsigned int cpu)
++{
++ struct rq *rq = cpu_rq(cpu);
++ unsigned long flags;
++
++ /* Handle pending wakeups and then migrate everything off */
++ sched_tick_stop(cpu);
++
++ raw_spin_lock_irqsave(&rq->lock, flags);
++ if (rq->nr_running != 1 || rq_has_pinned_tasks(rq)) {
++ WARN(true, "Dying CPU not properly vacated!");
++ dump_rq_tasks(rq, KERN_WARNING);
++ }
++ raw_spin_unlock_irqrestore(&rq->lock, flags);
++
++ /*
++ * Now that the CPU is offline, make sure we're welcome
++ * to new tasks once we come back up.
++ */
++ balance_push_set(cpu, false);
++
++ calc_load_migrate(rq);
++ hrtick_clear(rq);
++ return 0;
++}
++#endif
++
++#ifdef CONFIG_SMP
++static void sched_init_topology_cpumask_early(void)
++{
++ int cpu;
++ cpumask_t *tmp;
++
++ for_each_possible_cpu(cpu) {
++ /* init affinity masks */
++ tmp = per_cpu(sched_cpu_affinity_masks, cpu);
++
++ cpumask_copy(tmp, cpumask_of(cpu));
++ tmp++;
++ cpumask_copy(tmp, cpu_possible_mask);
++ cpumask_clear_cpu(cpu, tmp);
++ per_cpu(sched_cpu_affinity_end_mask, cpu) = ++tmp;
++ /* init topo masks */
++ tmp = per_cpu(sched_cpu_topo_masks, cpu);
++
++ cpumask_copy(tmp, cpumask_of(cpu));
++ tmp++;
++ cpumask_copy(tmp, cpu_possible_mask);
++ per_cpu(sched_cpu_llc_mask, cpu) = tmp;
++ /*per_cpu(sd_llc_id, cpu) = cpu;*/
++ }
++}
++
++#define TOPOLOGY_CPUMASK(name, mask, last) \
++ if (cpumask_and(chk, chk, mask)) { \
++ cpumask_copy(topo, mask); \
++ printk(KERN_INFO "sched: cpu#%02d affinity: 0x%08lx topo: 0x%08lx - "#name,\
++ cpu, (chk++)->bits[0], (topo++)->bits[0]); \
++ } \
++ if (!last) \
++ cpumask_complement(chk, mask)
++
++static void sched_init_topology_cpumask(void)
++{
++ int cpu;
++ cpumask_t *chk, *topo;
++
++ for_each_online_cpu(cpu) {
++ /* take chance to reset time slice for idle tasks */
++ cpu_rq(cpu)->idle->time_slice = sched_timeslice_ns;
++
++ chk = per_cpu(sched_cpu_affinity_masks, cpu) + 1;
++ topo = per_cpu(sched_cpu_topo_masks, cpu) + 1;
++
++ cpumask_complement(chk, cpumask_of(cpu));
++#ifdef CONFIG_SCHED_SMT
++ TOPOLOGY_CPUMASK(smt, topology_sibling_cpumask(cpu), false);
++#endif
++ per_cpu(sd_llc_id, cpu) = cpumask_first(cpu_coregroup_mask(cpu));
++ per_cpu(sched_cpu_llc_mask, cpu) = topo;
++ TOPOLOGY_CPUMASK(coregroup, cpu_coregroup_mask(cpu), false);
++
++ TOPOLOGY_CPUMASK(core, topology_core_cpumask(cpu), false);
++
++ TOPOLOGY_CPUMASK(others, cpu_online_mask, true);
++
++ per_cpu(sched_cpu_affinity_end_mask, cpu) = chk;
++ printk(KERN_INFO "sched: cpu#%02d llc_id = %d, llc_mask idx = %d\n",
++ cpu, per_cpu(sd_llc_id, cpu),
++ (int) (per_cpu(sched_cpu_llc_mask, cpu) -
++ per_cpu(sched_cpu_topo_masks, cpu)));
++ }
++}
++#endif
++
++void __init sched_init_smp(void)
++{
++ /* Move init over to a non-isolated CPU */
++ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0)
++ BUG();
++
++ sched_init_topology_cpumask();
++
++ sched_smp_initialized = true;
++}
++#else
++void __init sched_init_smp(void)
++{
++ cpu_rq(0)->idle->time_slice = sched_timeslice_ns;
++}
++#endif /* CONFIG_SMP */
++
++int in_sched_functions(unsigned long addr)
++{
++ return in_lock_functions(addr) ||
++ (addr >= (unsigned long)__sched_text_start
++ && addr < (unsigned long)__sched_text_end);
++}
++
++#ifdef CONFIG_CGROUP_SCHED
++/* task group related information */
++struct task_group {
++ struct cgroup_subsys_state css;
++
++ struct rcu_head rcu;
++ struct list_head list;
++
++ struct task_group *parent;
++ struct list_head siblings;
++ struct list_head children;
++#ifdef CONFIG_FAIR_GROUP_SCHED
++ unsigned long shares;
++#endif
++};
++
++/*
++ * Default task group.
++ * Every task in system belongs to this group at bootup.
++ */
++struct task_group root_task_group;
++LIST_HEAD(task_groups);
++
++/* Cacheline aligned slab cache for task_group */
++static struct kmem_cache *task_group_cache __read_mostly;
++#endif /* CONFIG_CGROUP_SCHED */
++
++void __init sched_init(void)
++{
++ int i;
++ struct rq *rq;
++
++ printk(KERN_INFO ALT_SCHED_VERSION_MSG);
++
++ wait_bit_init();
++
++#ifdef CONFIG_SMP
++ for (i = 0; i < SCHED_BITS; i++)
++ cpumask_copy(&sched_rq_watermark[i], cpu_present_mask);
++#endif
++
++#ifdef CONFIG_CGROUP_SCHED
++ task_group_cache = KMEM_CACHE(task_group, 0);
++
++ list_add(&root_task_group.list, &task_groups);
++ INIT_LIST_HEAD(&root_task_group.children);
++ INIT_LIST_HEAD(&root_task_group.siblings);
++#endif /* CONFIG_CGROUP_SCHED */
++ for_each_possible_cpu(i) {
++ rq = cpu_rq(i);
++
++ sched_queue_init(rq);
++ rq->watermark = IDLE_WM;
++ rq->skip = NULL;
++
++ raw_spin_lock_init(&rq->lock);
++ rq->nr_running = rq->nr_uninterruptible = 0;
++ rq->calc_load_active = 0;
++ rq->calc_load_update = jiffies + LOAD_FREQ;
++#ifdef CONFIG_SMP
++ rq->online = false;
++ rq->cpu = i;
++
++#ifdef CONFIG_SCHED_SMT
++ rq->active_balance = 0;
++#endif
++
++#ifdef CONFIG_NO_HZ_COMMON
++ INIT_CSD(&rq->nohz_csd, nohz_csd_func, rq);
++#endif
++ rq->balance_callback = NULL;
++#ifdef CONFIG_HOTPLUG_CPU
++ rcuwait_init(&rq->hotplug_wait);
++#endif
++#endif /* CONFIG_SMP */
++ rq->nr_switches = 0;
++
++ hrtick_rq_init(rq);
++ atomic_set(&rq->nr_iowait, 0);
++ }
++#ifdef CONFIG_SMP
++ /* Set rq->online for cpu 0 */
++ cpu_rq(0)->online = true;
++#endif
++ /*
++ * The boot idle thread does lazy MMU switching as well:
++ */
++ mmgrab(&init_mm);
++ enter_lazy_tlb(&init_mm, current);
++
++ /*
++ * Make us the idle thread. Technically, schedule() should not be
++ * called from this thread, however somewhere below it might be,
++ * but because we are the idle thread, we just pick up running again
++ * when this runqueue becomes "idle".
++ */
++ init_idle(current, smp_processor_id());
++
++ calc_load_update = jiffies + LOAD_FREQ;
++
++#ifdef CONFIG_SMP
++ idle_thread_set_boot_cpu();
++
++ sched_init_topology_cpumask_early();
++#endif /* SMP */
++
++ init_schedstats();
++
++ psi_init();
++}
++
++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
++static inline int preempt_count_equals(int preempt_offset)
++{
++ int nested = preempt_count() + rcu_preempt_depth();
++
++ return (nested == preempt_offset);
++}
++
++void __might_sleep(const char *file, int line, int preempt_offset)
++{
++ /*
++ * Blocking primitives will set (and therefore destroy) current->state,
++ * since we will exit with TASK_RUNNING make sure we enter with it,
++ * otherwise we will destroy state.
++ */
++ WARN_ONCE(current->state != TASK_RUNNING && current->task_state_change,
++ "do not call blocking ops when !TASK_RUNNING; "
++ "state=%lx set at [<%p>] %pS\n",
++ current->state,
++ (void *)current->task_state_change,
++ (void *)current->task_state_change);
++
++ ___might_sleep(file, line, preempt_offset);
++}
++EXPORT_SYMBOL(__might_sleep);
++
++void ___might_sleep(const char *file, int line, int preempt_offset)
++{
++ /* Ratelimiting timestamp: */
++ static unsigned long prev_jiffy;
++
++ unsigned long preempt_disable_ip;
++
++ /* WARN_ON_ONCE() by default, no rate limit required: */
++ rcu_sleep_check();
++
++ if ((preempt_count_equals(preempt_offset) && !irqs_disabled() &&
++ !is_idle_task(current) && !current->non_block_count) ||
++ system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING ||
++ oops_in_progress)
++ return;
++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
++ return;
++ prev_jiffy = jiffies;
++
++ /* Save this before calling printk(), since that will clobber it: */
++ preempt_disable_ip = get_preempt_disable_ip(current);
++
++ printk(KERN_ERR
++ "BUG: sleeping function called from invalid context at %s:%d\n",
++ file, line);
++ printk(KERN_ERR
++ "in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n",
++ in_atomic(), irqs_disabled(), current->non_block_count,
++ current->pid, current->comm);
++
++ if (task_stack_end_corrupted(current))
++ printk(KERN_EMERG "Thread overran stack, or stack corrupted\n");
++
++ debug_show_held_locks(current);
++ if (irqs_disabled())
++ print_irqtrace_events(current);
++#ifdef CONFIG_DEBUG_PREEMPT
++ if (!preempt_count_equals(preempt_offset)) {
++ pr_err("Preemption disabled at:");
++ print_ip_sym(KERN_ERR, preempt_disable_ip);
++ }
++#endif
++ dump_stack();
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
++}
++EXPORT_SYMBOL(___might_sleep);
++
++void __cant_sleep(const char *file, int line, int preempt_offset)
++{
++ static unsigned long prev_jiffy;
++
++ if (irqs_disabled())
++ return;
++
++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT))
++ return;
++
++ if (preempt_count() > preempt_offset)
++ return;
++
++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
++ return;
++ prev_jiffy = jiffies;
++
++ printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line);
++ printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
++ in_atomic(), irqs_disabled(),
++ current->pid, current->comm);
++
++ debug_show_held_locks(current);
++ dump_stack();
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
++}
++EXPORT_SYMBOL_GPL(__cant_sleep);
++
++#ifdef CONFIG_SMP
++void __cant_migrate(const char *file, int line)
++{
++ static unsigned long prev_jiffy;
++
++ if (irqs_disabled())
++ return;
++
++ if (is_migration_disabled(current))
++ return;
++
++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT))
++ return;
++
++ if (preempt_count() > 0)
++ return;
++
++ if (current->migration_flags & MDF_FORCE_ENABLED)
++ return;
++
++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
++ return;
++ prev_jiffy = jiffies;
++
++ pr_err("BUG: assuming non migratable context at %s:%d\n", file, line);
++ pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n",
++ in_atomic(), irqs_disabled(), is_migration_disabled(current),
++ current->pid, current->comm);
++
++ debug_show_held_locks(current);
++ dump_stack();
++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
++}
++EXPORT_SYMBOL_GPL(__cant_migrate);
++#endif
++#endif
++
++#ifdef CONFIG_MAGIC_SYSRQ
++void normalize_rt_tasks(void)
++{
++ struct task_struct *g, *p;
++ struct sched_attr attr = {
++ .sched_policy = SCHED_NORMAL,
++ };
++
++ read_lock(&tasklist_lock);
++ for_each_process_thread(g, p) {
++ /*
++ * Only normalize user tasks:
++ */
++ if (p->flags & PF_KTHREAD)
++ continue;
++
++ if (!rt_task(p)) {
++ /*
++ * Renice negative nice level userspace
++ * tasks back to 0:
++ */
++ if (task_nice(p) < 0)
++ set_user_nice(p, 0);
++ continue;
++ }
++
++ __sched_setscheduler(p, &attr, false, false);
++ }
++ read_unlock(&tasklist_lock);
++}
++#endif /* CONFIG_MAGIC_SYSRQ */
++
++#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
++/*
++ * These functions are only useful for the IA64 MCA handling, or kdb.
++ *
++ * They can only be called when the whole system has been
++ * stopped - every CPU needs to be quiescent, and no scheduling
++ * activity can take place. Using them for anything else would
++ * be a serious bug, and as a result, they aren't even visible
++ * under any other configuration.
++ */
++
++/**
++ * curr_task - return the current task for a given CPU.
++ * @cpu: the processor in question.
++ *
++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
++ *
++ * Return: The current task for @cpu.
++ */
++struct task_struct *curr_task(int cpu)
++{
++ return cpu_curr(cpu);
++}
++
++#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
++
++#ifdef CONFIG_IA64
++/**
++ * ia64_set_curr_task - set the current task for a given CPU.
++ * @cpu: the processor in question.
++ * @p: the task pointer to set.
++ *
++ * Description: This function must only be used when non-maskable interrupts
++ * are serviced on a separate stack. It allows the architecture to switch the
++ * notion of the current task on a CPU in a non-blocking manner. This function
++ * must be called with all CPU's synchronised, and interrupts disabled, the
++ * and caller must save the original value of the current task (see
++ * curr_task() above) and restore that value before reenabling interrupts and
++ * re-starting the system.
++ *
++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
++ */
++void ia64_set_curr_task(int cpu, struct task_struct *p)
++{
++ cpu_curr(cpu) = p;
++}
++
++#endif
++
++#ifdef CONFIG_CGROUP_SCHED
++static void sched_free_group(struct task_group *tg)
++{
++ kmem_cache_free(task_group_cache, tg);
++}
++
++/* allocate runqueue etc for a new task group */
++struct task_group *sched_create_group(struct task_group *parent)
++{
++ struct task_group *tg;
++
++ tg = kmem_cache_alloc(task_group_cache, GFP_KERNEL | __GFP_ZERO);
++ if (!tg)
++ return ERR_PTR(-ENOMEM);
++
++ return tg;
++}
++
++void sched_online_group(struct task_group *tg, struct task_group *parent)
++{
++}
++
++/* rcu callback to free various structures associated with a task group */
++static void sched_free_group_rcu(struct rcu_head *rhp)
++{
++ /* Now it should be safe to free those cfs_rqs */
++ sched_free_group(container_of(rhp, struct task_group, rcu));
++}
++
++void sched_destroy_group(struct task_group *tg)
++{
++ /* Wait for possible concurrent references to cfs_rqs complete */
++ call_rcu(&tg->rcu, sched_free_group_rcu);
++}
++
++void sched_offline_group(struct task_group *tg)
++{
++}
++
++static inline struct task_group *css_tg(struct cgroup_subsys_state *css)
++{
++ return css ? container_of(css, struct task_group, css) : NULL;
++}
++
++static struct cgroup_subsys_state *
++cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
++{
++ struct task_group *parent = css_tg(parent_css);
++ struct task_group *tg;
++
++ if (!parent) {
++ /* This is early initialization for the top cgroup */
++ return &root_task_group.css;
++ }
++
++ tg = sched_create_group(parent);
++ if (IS_ERR(tg))
++ return ERR_PTR(-ENOMEM);
++ return &tg->css;
++}
++
++/* Expose task group only after completing cgroup initialization */
++static int cpu_cgroup_css_online(struct cgroup_subsys_state *css)
++{
++ struct task_group *tg = css_tg(css);
++ struct task_group *parent = css_tg(css->parent);
++
++ if (parent)
++ sched_online_group(tg, parent);
++ return 0;
++}
++
++static void cpu_cgroup_css_released(struct cgroup_subsys_state *css)
++{
++ struct task_group *tg = css_tg(css);
++
++ sched_offline_group(tg);
++}
++
++static void cpu_cgroup_css_free(struct cgroup_subsys_state *css)
++{
++ struct task_group *tg = css_tg(css);
++
++ /*
++ * Relies on the RCU grace period between css_released() and this.
++ */
++ sched_free_group(tg);
++}
++
++static void cpu_cgroup_fork(struct task_struct *task)
++{
++}
++
++static int cpu_cgroup_can_attach(struct cgroup_taskset *tset)
++{
++ return 0;
++}
++
++static void cpu_cgroup_attach(struct cgroup_taskset *tset)
++{
++}
++
++#ifdef CONFIG_FAIR_GROUP_SCHED
++static DEFINE_MUTEX(shares_mutex);
++
++int sched_group_set_shares(struct task_group *tg, unsigned long shares)
++{
++ /*
++ * We can't change the weight of the root cgroup.
++ */
++ if (&root_task_group == tg)
++ return -EINVAL;
++
++ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES));
++
++ mutex_lock(&shares_mutex);
++ if (tg->shares == shares)
++ goto done;
++
++ tg->shares = shares;
++done:
++ mutex_unlock(&shares_mutex);
++ return 0;
++}
++
++static int cpu_shares_write_u64(struct cgroup_subsys_state *css,
++ struct cftype *cftype, u64 shareval)
++{
++ if (shareval > scale_load_down(ULONG_MAX))
++ shareval = MAX_SHARES;
++ return sched_group_set_shares(css_tg(css), scale_load(shareval));
++}
++
++static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css,
++ struct cftype *cft)
++{
++ struct task_group *tg = css_tg(css);
++
++ return (u64) scale_load_down(tg->shares);
++}
++#endif
++
++static struct cftype cpu_legacy_files[] = {
++#ifdef CONFIG_FAIR_GROUP_SCHED
++ {
++ .name = "shares",
++ .read_u64 = cpu_shares_read_u64,
++ .write_u64 = cpu_shares_write_u64,
++ },
++#endif
++ { } /* Terminate */
++};
++
++
++static struct cftype cpu_files[] = {
++ { } /* terminate */
++};
++
++static int cpu_extra_stat_show(struct seq_file *sf,
++ struct cgroup_subsys_state *css)
++{
++ return 0;
++}
++
++struct cgroup_subsys cpu_cgrp_subsys = {
++ .css_alloc = cpu_cgroup_css_alloc,
++ .css_online = cpu_cgroup_css_online,
++ .css_released = cpu_cgroup_css_released,
++ .css_free = cpu_cgroup_css_free,
++ .css_extra_stat_show = cpu_extra_stat_show,
++ .fork = cpu_cgroup_fork,
++ .can_attach = cpu_cgroup_can_attach,
++ .attach = cpu_cgroup_attach,
++ .legacy_cftypes = cpu_files,
++ .legacy_cftypes = cpu_legacy_files,
++ .dfl_cftypes = cpu_files,
++ .early_init = true,
++ .threaded = true,
++};
++#endif /* CONFIG_CGROUP_SCHED */
++
++#undef CREATE_TRACE_POINTS
+diff --git a/kernel/sched/alt_debug.c b/kernel/sched/alt_debug.c
+new file mode 100644
+index 000000000000..1212a031700e
+--- /dev/null
++++ b/kernel/sched/alt_debug.c
+@@ -0,0 +1,31 @@
++/*
++ * kernel/sched/alt_debug.c
++ *
++ * Print the alt scheduler debugging details
++ *
++ * Author: Alfred Chen
++ * Date : 2020
++ */
++#include "sched.h"
++
++/*
++ * This allows printing both to /proc/sched_debug and
++ * to the console
++ */
++#define SEQ_printf(m, x...) \
++ do { \
++ if (m) \
++ seq_printf(m, x); \
++ else \
++ pr_cont(x); \
++ } while (0)
++
++void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
++ struct seq_file *m)
++{
++ SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns),
++ get_nr_threads(p));
++}
++
++void proc_sched_set_task(struct task_struct *p)
++{}
+diff --git a/kernel/sched/alt_sched.h b/kernel/sched/alt_sched.h
+new file mode 100644
+index 000000000000..2a6a0530fbb7
+--- /dev/null
++++ b/kernel/sched/alt_sched.h
+@@ -0,0 +1,686 @@
++#ifndef ALT_SCHED_H
++#define ALT_SCHED_H
++
++#include <linux/sched.h>
++
++#include <linux/sched/clock.h>
++#include <linux/sched/cpufreq.h>
++#include <linux/sched/cputime.h>
++#include <linux/sched/debug.h>
++#include <linux/sched/init.h>
++#include <linux/sched/isolation.h>
++#include <linux/sched/loadavg.h>
++#include <linux/sched/mm.h>
++#include <linux/sched/nohz.h>
++#include <linux/sched/signal.h>
++#include <linux/sched/stat.h>
++#include <linux/sched/sysctl.h>
++#include <linux/sched/task.h>
++#include <linux/sched/topology.h>
++#include <linux/sched/wake_q.h>
++
++#include <uapi/linux/sched/types.h>
++
++#include <linux/cgroup.h>
++#include <linux/cpufreq.h>
++#include <linux/cpuidle.h>
++#include <linux/cpuset.h>
++#include <linux/ctype.h>
++#include <linux/debugfs.h>
++#include <linux/kthread.h>
++#include <linux/livepatch.h>
++#include <linux/membarrier.h>
++#include <linux/proc_fs.h>
++#include <linux/psi.h>
++#include <linux/slab.h>
++#include <linux/stop_machine.h>
++#include <linux/suspend.h>
++#include <linux/swait.h>
++#include <linux/syscalls.h>
++#include <linux/tsacct_kern.h>
++
++#include <asm/tlb.h>
++
++#ifdef CONFIG_PARAVIRT
++# include <asm/paravirt.h>
++#endif
++
++#include "cpupri.h"
++
++#include <trace/events/sched.h>
++
++#ifdef CONFIG_SCHED_BMQ
++#include "bmq.h"
++#endif
++#ifdef CONFIG_SCHED_PDS
++#include "pds.h"
++#endif
++
++#ifdef CONFIG_SCHED_DEBUG
++# define SCHED_WARN_ON(x) WARN_ONCE(x, #x)
++#else
++# define SCHED_WARN_ON(x) ({ (void)(x), 0; })
++#endif
++
++/*
++ * Increase resolution of nice-level calculations for 64-bit architectures.
++ * The extra resolution improves shares distribution and load balancing of
++ * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
++ * hierarchies, especially on larger systems. This is not a user-visible change
++ * and does not change the user-interface for setting shares/weights.
++ *
++ * We increase resolution only if we have enough bits to allow this increased
++ * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
++ * are pretty high and the returns do not justify the increased costs.
++ *
++ * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to
++ * increase coverage and consistency always enable it on 64-bit platforms.
++ */
++#ifdef CONFIG_64BIT
++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
++# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
++# define scale_load_down(w) \
++({ \
++ unsigned long __w = (w); \
++ if (__w) \
++ __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
++ __w; \
++})
++#else
++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
++# define scale_load(w) (w)
++# define scale_load_down(w) (w)
++#endif
++
++#ifdef CONFIG_FAIR_GROUP_SCHED
++#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
++
++/*
++ * A weight of 0 or 1 can cause arithmetics problems.
++ * A weight of a cfs_rq is the sum of weights of which entities
++ * are queued on this cfs_rq, so a weight of a entity should not be
++ * too large, so as the shares value of a task group.
++ * (The default weight is 1024 - so there's no practical
++ * limitation from this.)
++ */
++#define MIN_SHARES (1UL << 1)
++#define MAX_SHARES (1UL << 18)
++#endif
++
++/* task_struct::on_rq states: */
++#define TASK_ON_RQ_QUEUED 1
++#define TASK_ON_RQ_MIGRATING 2
++
++static inline int task_on_rq_queued(struct task_struct *p)
++{
++ return p->on_rq == TASK_ON_RQ_QUEUED;
++}
++
++static inline int task_on_rq_migrating(struct task_struct *p)
++{
++ return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
++}
++
++/*
++ * wake flags
++ */
++#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
++#define WF_FORK 0x02 /* child wakeup after fork */
++#define WF_MIGRATED 0x04 /* internal use, task got migrated */
++#define WF_ON_CPU 0x08 /* Wakee is on_rq */
++
++/*
++ * This is the main, per-CPU runqueue data structure.
++ * This data should only be modified by the local cpu.
++ */
++struct rq {
++ /* runqueue lock: */
++ raw_spinlock_t lock;
++
++ struct task_struct __rcu *curr;
++ struct task_struct *idle, *stop, *skip;
++ struct mm_struct *prev_mm;
++
++#ifdef CONFIG_SCHED_BMQ
++ struct bmq queue;
++#endif
++#ifdef CONFIG_SCHED_PDS
++ struct skiplist_node sl_header;
++#endif
++ unsigned long watermark;
++
++ /* switch count */
++ u64 nr_switches;
++
++ atomic_t nr_iowait;
++
++#ifdef CONFIG_MEMBARRIER
++ int membarrier_state;
++#endif
++
++#ifdef CONFIG_SMP
++ int cpu; /* cpu of this runqueue */
++ bool online;
++
++ unsigned int ttwu_pending;
++ unsigned char nohz_idle_balance;
++ unsigned char idle_balance;
++
++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
++ struct sched_avg avg_irq;
++#endif
++
++#ifdef CONFIG_SCHED_SMT
++ int active_balance;
++ struct cpu_stop_work active_balance_work;
++#endif
++ struct callback_head *balance_callback;
++ unsigned char balance_push;
++#ifdef CONFIG_HOTPLUG_CPU
++ struct rcuwait hotplug_wait;
++#endif
++ unsigned int nr_pinned;
++#endif /* CONFIG_SMP */
++#ifdef CONFIG_IRQ_TIME_ACCOUNTING
++ u64 prev_irq_time;
++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
++#ifdef CONFIG_PARAVIRT
++ u64 prev_steal_time;
++#endif /* CONFIG_PARAVIRT */
++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
++ u64 prev_steal_time_rq;
++#endif /* CONFIG_PARAVIRT_TIME_ACCOUNTING */
++
++ /* calc_load related fields */
++ unsigned long calc_load_update;
++ long calc_load_active;
++
++ u64 clock, last_tick;
++ u64 last_ts_switch;
++ u64 clock_task;
++
++ unsigned int nr_running;
++ unsigned long nr_uninterruptible;
++
++#ifdef CONFIG_SCHED_HRTICK
++#ifdef CONFIG_SMP
++ call_single_data_t hrtick_csd;
++#endif
++ struct hrtimer hrtick_timer;
++ ktime_t hrtick_time;
++#endif
++
++#ifdef CONFIG_SCHEDSTATS
++
++ /* latency stats */
++ struct sched_info rq_sched_info;
++ unsigned long long rq_cpu_time;
++ /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
++
++ /* sys_sched_yield() stats */
++ unsigned int yld_count;
++
++ /* schedule() stats */
++ unsigned int sched_switch;
++ unsigned int sched_count;
++ unsigned int sched_goidle;
++
++ /* try_to_wake_up() stats */
++ unsigned int ttwu_count;
++ unsigned int ttwu_local;
++#endif /* CONFIG_SCHEDSTATS */
++
++#ifdef CONFIG_CPU_IDLE
++ /* Must be inspected within a rcu lock section */
++ struct cpuidle_state *idle_state;
++#endif
++
++#ifdef CONFIG_NO_HZ_COMMON
++#ifdef CONFIG_SMP
++ call_single_data_t nohz_csd;
++#endif
++ atomic_t nohz_flags;
++#endif /* CONFIG_NO_HZ_COMMON */
++};
++
++extern unsigned long calc_load_update;
++extern atomic_long_t calc_load_tasks;
++
++extern void calc_global_load_tick(struct rq *this_rq);
++extern long calc_load_fold_active(struct rq *this_rq, long adjust);
++
++DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
++#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
++#define this_rq() this_cpu_ptr(&runqueues)
++#define task_rq(p) cpu_rq(task_cpu(p))
++#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
++#define raw_rq() raw_cpu_ptr(&runqueues)
++
++#ifdef CONFIG_SMP
++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
++void register_sched_domain_sysctl(void);
++void unregister_sched_domain_sysctl(void);
++#else
++static inline void register_sched_domain_sysctl(void)
++{
++}
++static inline void unregister_sched_domain_sysctl(void)
++{
++}
++#endif
++
++extern bool sched_smp_initialized;
++
++enum {
++ ITSELF_LEVEL_SPACE_HOLDER,
++#ifdef CONFIG_SCHED_SMT
++ SMT_LEVEL_SPACE_HOLDER,
++#endif
++ COREGROUP_LEVEL_SPACE_HOLDER,
++ CORE_LEVEL_SPACE_HOLDER,
++ OTHER_LEVEL_SPACE_HOLDER,
++ NR_CPU_AFFINITY_LEVELS
++};
++
++DECLARE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks);
++DECLARE_PER_CPU(cpumask_t *, sched_cpu_llc_mask);
++
++static inline int __best_mask_cpu(int cpu, const cpumask_t *cpumask,
++ const cpumask_t *mask)
++{
++#if NR_CPUS <= 64
++ unsigned long t;
++
++ while ((t = cpumask->bits[0] & mask->bits[0]) == 0UL)
++ mask++;
++
++ return __ffs(t);
++#else
++ while ((cpu = cpumask_any_and(cpumask, mask)) >= nr_cpu_ids)
++ mask++;
++ return cpu;
++#endif
++}
++
++static inline int best_mask_cpu(int cpu, const cpumask_t *mask)
++{
++#if NR_CPUS <= 64
++ unsigned long llc_match;
++ cpumask_t *chk = per_cpu(sched_cpu_llc_mask, cpu);
++
++ if ((llc_match = mask->bits[0] & chk->bits[0])) {
++ unsigned long match;
++
++ chk = per_cpu(sched_cpu_topo_masks, cpu);
++ if (mask->bits[0] & chk->bits[0])
++ return cpu;
++
++#ifdef CONFIG_SCHED_SMT
++ chk++;
++ if ((match = mask->bits[0] & chk->bits[0]))
++ return __ffs(match);
++#endif
++
++ return __ffs(llc_match);
++ }
++
++ return __best_mask_cpu(cpu, mask, chk + 1);
++#else
++ cpumask_t llc_match;
++ cpumask_t *chk = per_cpu(sched_cpu_llc_mask, cpu);
++
++ if (cpumask_and(&llc_match, mask, chk)) {
++ cpumask_t tmp;
++
++ chk = per_cpu(sched_cpu_topo_masks, cpu);
++ if (cpumask_test_cpu(cpu, mask))
++ return cpu;
++
++#ifdef CONFIG_SCHED_SMT
++ chk++;
++ if (cpumask_and(&tmp, mask, chk))
++ return cpumask_any(&tmp);
++#endif
++
++ return cpumask_any(&llc_match);
++ }
++
++ return __best_mask_cpu(cpu, mask, chk + 1);
++#endif
++}
++
++extern void flush_smp_call_function_from_idle(void);
++
++#else /* !CONFIG_SMP */
++static inline void flush_smp_call_function_from_idle(void) { }
++#endif
++
++#ifndef arch_scale_freq_tick
++static __always_inline
++void arch_scale_freq_tick(void)
++{
++}
++#endif
++
++#ifndef arch_scale_freq_capacity
++static __always_inline
++unsigned long arch_scale_freq_capacity(int cpu)
++{
++ return SCHED_CAPACITY_SCALE;
++}
++#endif
++
++static inline u64 __rq_clock_broken(struct rq *rq)
++{
++ return READ_ONCE(rq->clock);
++}
++
++static inline u64 rq_clock(struct rq *rq)
++{
++ /*
++ * Relax lockdep_assert_held() checking as in VRQ, call to
++ * sched_info_xxxx() may not held rq->lock
++ * lockdep_assert_held(&rq->lock);
++ */
++ return rq->clock;
++}
++
++static inline u64 rq_clock_task(struct rq *rq)
++{
++ /*
++ * Relax lockdep_assert_held() checking as in VRQ, call to
++ * sched_info_xxxx() may not held rq->lock
++ * lockdep_assert_held(&rq->lock);
++ */
++ return rq->clock_task;
++}
++
++/*
++ * {de,en}queue flags:
++ *
++ * DEQUEUE_SLEEP - task is no longer runnable
++ * ENQUEUE_WAKEUP - task just became runnable
++ *
++ */
++
++#define DEQUEUE_SLEEP 0x01
++
++#define ENQUEUE_WAKEUP 0x01
++
++
++/*
++ * Below are scheduler API which using in other kernel code
++ * It use the dummy rq_flags
++ * ToDo : BMQ need to support these APIs for compatibility with mainline
++ * scheduler code.
++ */
++struct rq_flags {
++ unsigned long flags;
++};
++
++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
++ __acquires(rq->lock);
++
++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
++ __acquires(p->pi_lock)
++ __acquires(rq->lock);
++
++static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
++ __releases(rq->lock)
++{
++ raw_spin_unlock(&rq->lock);
++}
++
++static inline void
++task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
++ __releases(rq->lock)
++ __releases(p->pi_lock)
++{
++ raw_spin_unlock(&rq->lock);
++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
++}
++
++static inline void
++rq_lock(struct rq *rq, struct rq_flags *rf)
++ __acquires(rq->lock)
++{
++ raw_spin_lock(&rq->lock);
++}
++
++static inline void
++rq_unlock_irq(struct rq *rq, struct rq_flags *rf)
++ __releases(rq->lock)
++{
++ raw_spin_unlock_irq(&rq->lock);
++}
++
++static inline void
++rq_unlock(struct rq *rq, struct rq_flags *rf)
++ __releases(rq->lock)
++{
++ raw_spin_unlock(&rq->lock);
++}
++
++static inline struct rq *
++this_rq_lock_irq(struct rq_flags *rf)
++ __acquires(rq->lock)
++{
++ struct rq *rq;
++
++ local_irq_disable();
++ rq = this_rq();
++ raw_spin_lock(&rq->lock);
++
++ return rq;
++}
++
++static inline int task_current(struct rq *rq, struct task_struct *p)
++{
++ return rq->curr == p;
++}
++
++static inline bool task_running(struct task_struct *p)
++{
++ return p->on_cpu;
++}
++
++extern int task_running_nice(struct task_struct *p);
++
++extern struct static_key_false sched_schedstats;
++
++#ifdef CONFIG_CPU_IDLE
++static inline void idle_set_state(struct rq *rq,
++ struct cpuidle_state *idle_state)
++{
++ rq->idle_state = idle_state;
++}
++
++static inline struct cpuidle_state *idle_get_state(struct rq *rq)
++{
++ WARN_ON(!rcu_read_lock_held());
++ return rq->idle_state;
++}
++#else
++static inline void idle_set_state(struct rq *rq,
++ struct cpuidle_state *idle_state)
++{
++}
++
++static inline struct cpuidle_state *idle_get_state(struct rq *rq)
++{
++ return NULL;
++}
++#endif
++
++static inline int cpu_of(const struct rq *rq)
++{
++#ifdef CONFIG_SMP
++ return rq->cpu;
++#else
++ return 0;
++#endif
++}
++
++#include "stats.h"
++
++#ifdef CONFIG_NO_HZ_COMMON
++#define NOHZ_BALANCE_KICK_BIT 0
++#define NOHZ_STATS_KICK_BIT 1
++
++#define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT)
++#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT)
++
++#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK)
++
++#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
++
++/* TODO: needed?
++extern void nohz_balance_exit_idle(struct rq *rq);
++#else
++static inline void nohz_balance_exit_idle(struct rq *rq) { }
++*/
++#endif
++
++#ifdef CONFIG_IRQ_TIME_ACCOUNTING
++struct irqtime {
++ u64 total;
++ u64 tick_delta;
++ u64 irq_start_time;
++ struct u64_stats_sync sync;
++};
++
++DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
++
++/*
++ * Returns the irqtime minus the softirq time computed by ksoftirqd.
++ * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime
++ * and never move forward.
++ */
++static inline u64 irq_time_read(int cpu)
++{
++ struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
++ unsigned int seq;
++ u64 total;
++
++ do {
++ seq = __u64_stats_fetch_begin(&irqtime->sync);
++ total = irqtime->total;
++ } while (__u64_stats_fetch_retry(&irqtime->sync, seq));
++
++ return total;
++}
++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
++
++#ifdef CONFIG_CPU_FREQ
++DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
++
++/**
++ * cpufreq_update_util - Take a note about CPU utilization changes.
++ * @rq: Runqueue to carry out the update for.
++ * @flags: Update reason flags.
++ *
++ * This function is called by the scheduler on the CPU whose utilization is
++ * being updated.
++ *
++ * It can only be called from RCU-sched read-side critical sections.
++ *
++ * The way cpufreq is currently arranged requires it to evaluate the CPU
++ * performance state (frequency/voltage) on a regular basis to prevent it from
++ * being stuck in a completely inadequate performance level for too long.
++ * That is not guaranteed to happen if the updates are only triggered from CFS
++ * and DL, though, because they may not be coming in if only RT tasks are
++ * active all the time (or there are RT tasks only).
++ *
++ * As a workaround for that issue, this function is called periodically by the
++ * RT sched class to trigger extra cpufreq updates to prevent it from stalling,
++ * but that really is a band-aid. Going forward it should be replaced with
++ * solutions targeted more specifically at RT tasks.
++ */
++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
++{
++ struct update_util_data *data;
++
++ data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data,
++ cpu_of(rq)));
++ if (data)
++ data->func(data, rq_clock(rq), flags);
++}
++#else
++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
++#endif /* CONFIG_CPU_FREQ */
++
++#ifdef CONFIG_NO_HZ_FULL
++extern int __init sched_tick_offload_init(void);
++#else
++static inline int sched_tick_offload_init(void) { return 0; }
++#endif
++
++#ifdef arch_scale_freq_capacity
++#ifndef arch_scale_freq_invariant
++#define arch_scale_freq_invariant() (true)
++#endif
++#else /* arch_scale_freq_capacity */
++#define arch_scale_freq_invariant() (false)
++#endif
++
++extern void schedule_idle(void);
++
++#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
++
++/*
++ * !! For sched_setattr_nocheck() (kernel) only !!
++ *
++ * This is actually gross. :(
++ *
++ * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE
++ * tasks, but still be able to sleep. We need this on platforms that cannot
++ * atomically change clock frequency. Remove once fast switching will be
++ * available on such platforms.
++ *
++ * SUGOV stands for SchedUtil GOVernor.
++ */
++#define SCHED_FLAG_SUGOV 0x10000000
++
++#ifdef CONFIG_MEMBARRIER
++/*
++ * The scheduler provides memory barriers required by membarrier between:
++ * - prior user-space memory accesses and store to rq->membarrier_state,
++ * - store to rq->membarrier_state and following user-space memory accesses.
++ * In the same way it provides those guarantees around store to rq->curr.
++ */
++static inline void membarrier_switch_mm(struct rq *rq,
++ struct mm_struct *prev_mm,
++ struct mm_struct *next_mm)
++{
++ int membarrier_state;
++
++ if (prev_mm == next_mm)
++ return;
++
++ membarrier_state = atomic_read(&next_mm->membarrier_state);
++ if (READ_ONCE(rq->membarrier_state) == membarrier_state)
++ return;
++
++ WRITE_ONCE(rq->membarrier_state, membarrier_state);
++}
++#else
++static inline void membarrier_switch_mm(struct rq *rq,
++ struct mm_struct *prev_mm,
++ struct mm_struct *next_mm)
++{
++}
++#endif
++
++#ifdef CONFIG_NUMA
++extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
++#else
++static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
++{
++ return nr_cpu_ids;
++}
++#endif
++
++void swake_up_all_locked(struct swait_queue_head *q);
++void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
++
++#endif /* ALT_SCHED_H */
+diff --git a/kernel/sched/bmq.h b/kernel/sched/bmq.h
+new file mode 100644
+index 000000000000..aba3c98759f8
+--- /dev/null
++++ b/kernel/sched/bmq.h
+@@ -0,0 +1,14 @@
++#ifndef BMQ_H
++#define BMQ_H
++
++/* bits:
++ * RT(0-99), (Low prio adj range, nice width, high prio adj range) / 2, cpu idle task */
++#define SCHED_BITS (MAX_RT_PRIO + NICE_WIDTH / 2 + MAX_PRIORITY_ADJ + 1)
++#define IDLE_TASK_SCHED_PRIO (SCHED_BITS - 1)
++
++struct bmq {
++ DECLARE_BITMAP(bitmap, SCHED_BITS);
++ struct list_head heads[SCHED_BITS];
++};
++
++#endif
+diff --git a/kernel/sched/bmq_imp.h b/kernel/sched/bmq_imp.h
+new file mode 100644
+index 000000000000..7c71f1141d00
+--- /dev/null
++++ b/kernel/sched/bmq_imp.h
+@@ -0,0 +1,203 @@
++#define ALT_SCHED_VERSION_MSG "sched/bmq: BMQ CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n"
++
++/*
++ * BMQ only routines
++ */
++#define rq_switch_time(rq) ((rq)->clock - (rq)->last_ts_switch)
++#define boost_threshold(p) (sched_timeslice_ns >>\
++ (15 - MAX_PRIORITY_ADJ - (p)->boost_prio))
++
++static inline void boost_task(struct task_struct *p)
++{
++ int limit;
++
++ switch (p->policy) {
++ case SCHED_NORMAL:
++ limit = -MAX_PRIORITY_ADJ;
++ break;
++ case SCHED_BATCH:
++ case SCHED_IDLE:
++ limit = 0;
++ break;
++ default:
++ return;
++ }
++
++ if (p->boost_prio > limit)
++ p->boost_prio--;
++}
++
++static inline void deboost_task(struct task_struct *p)
++{
++ if (p->boost_prio < MAX_PRIORITY_ADJ)
++ p->boost_prio++;
++}
++
++/*
++ * Common interfaces
++ */
++static inline int normal_prio(struct task_struct *p)
++{
++ if (task_has_rt_policy(p))
++ return MAX_RT_PRIO - 1 - p->rt_priority;
++
++ return p->static_prio + MAX_PRIORITY_ADJ;
++}
++
++static inline int task_sched_prio(struct task_struct *p, struct rq *rq)
++{
++ return (p->prio < MAX_RT_PRIO)? p->prio : MAX_RT_PRIO / 2 + (p->prio + p->boost_prio) / 2;
++}
++
++static inline void requeue_task(struct task_struct *p, struct rq *rq);
++
++static inline void time_slice_expired(struct task_struct *p, struct rq *rq)
++{
++ p->time_slice = sched_timeslice_ns;
++
++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) {
++ if (SCHED_RR != p->policy)
++ deboost_task(p);
++ requeue_task(p, rq);
++ }
++}
++
++inline int task_running_nice(struct task_struct *p)
++{
++ return (p->prio + p->boost_prio > DEFAULT_PRIO + MAX_PRIORITY_ADJ);
++}
++
++static inline void update_task_priodl(struct task_struct *p) {}
++
++static inline unsigned long sched_queue_watermark(struct rq *rq)
++{
++ return find_first_bit(rq->queue.bitmap, SCHED_BITS);
++}
++
++static inline void sched_queue_init(struct rq *rq)
++{
++ struct bmq *q = &rq->queue;
++ int i;
++
++ bitmap_zero(q->bitmap, SCHED_BITS);
++ for(i = 0; i < SCHED_BITS; i++)
++ INIT_LIST_HEAD(&q->heads[i]);
++}
++
++static inline void sched_queue_init_idle(struct rq *rq, struct task_struct *idle)
++{
++ struct bmq *q = &rq->queue;
++
++ idle->bmq_idx = IDLE_TASK_SCHED_PRIO;
++ INIT_LIST_HEAD(&q->heads[idle->bmq_idx]);
++ list_add(&idle->bmq_node, &q->heads[idle->bmq_idx]);
++ set_bit(idle->bmq_idx, q->bitmap);
++}
++
++/*
++ * This routine used in bmq scheduler only which assume the idle task in the bmq
++ */
++static inline struct task_struct *sched_rq_first_task(struct rq *rq)
++{
++ unsigned long idx = find_first_bit(rq->queue.bitmap, SCHED_BITS);
++ const struct list_head *head = &rq->queue.heads[idx];
++
++ return list_first_entry(head, struct task_struct, bmq_node);
++}
++
++static inline struct task_struct *
++sched_rq_next_task(struct task_struct *p, struct rq *rq)
++{
++ unsigned long idx = p->bmq_idx;
++ struct list_head *head = &rq->queue.heads[idx];
++
++ if (list_is_last(&p->bmq_node, head)) {
++ idx = find_next_bit(rq->queue.bitmap, SCHED_BITS, idx + 1);
++ head = &rq->queue.heads[idx];
++
++ return list_first_entry(head, struct task_struct, bmq_node);
++ }
++
++ return list_next_entry(p, bmq_node);
++}
++
++#define __SCHED_DEQUEUE_TASK(p, rq, flags, func) \
++ psi_dequeue(p, flags & DEQUEUE_SLEEP); \
++ sched_info_dequeued(rq, p); \
++ \
++ list_del(&p->bmq_node); \
++ if (list_empty(&rq->queue.heads[p->bmq_idx])) { \
++ clear_bit(p->bmq_idx, rq->queue.bitmap);\
++ func; \
++ }
++
++#define __SCHED_ENQUEUE_TASK(p, rq, flags) \
++ sched_info_queued(rq, p); \
++ psi_enqueue(p, flags); \
++ \
++ p->bmq_idx = task_sched_prio(p, rq); \
++ list_add_tail(&p->bmq_node, &rq->queue.heads[p->bmq_idx]); \
++ set_bit(p->bmq_idx, rq->queue.bitmap)
++
++#define __SCHED_REQUEUE_TASK(p, rq, func) \
++{ \
++ int idx = task_sched_prio(p, rq); \
++\
++ list_del(&p->bmq_node); \
++ list_add_tail(&p->bmq_node, &rq->queue.heads[idx]); \
++ if (idx != p->bmq_idx) { \
++ if (list_empty(&rq->queue.heads[p->bmq_idx])) \
++ clear_bit(p->bmq_idx, rq->queue.bitmap); \
++ p->bmq_idx = idx; \
++ set_bit(p->bmq_idx, rq->queue.bitmap); \
++ func; \
++ } \
++}
++
++static inline bool sched_task_need_requeue(struct task_struct *p, struct rq *rq)
++{
++ return (task_sched_prio(p, rq) != p->bmq_idx);
++}
++
++static void sched_task_fork(struct task_struct *p, struct rq *rq)
++{
++ p->boost_prio = (p->boost_prio < 0) ?
++ p->boost_prio + MAX_PRIORITY_ADJ : MAX_PRIORITY_ADJ;
++}
++
++/**
++ * task_prio - return the priority value of a given task.
++ * @p: the task in question.
++ *
++ * Return: The priority value as seen by users in /proc.
++ *
++ * sched policy return value kernel prio user prio/nice/boost
++ *
++ * normal, batch, idle [0 ... 53] [100 ... 139] 0/[-20 ... 19]/[-7 ... 7]
++ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99]
++ */
++int task_prio(const struct task_struct *p)
++{
++ if (p->prio < MAX_RT_PRIO)
++ return (p->prio - MAX_RT_PRIO);
++ return (p->prio - MAX_RT_PRIO + p->boost_prio);
++}
++
++static void do_sched_yield_type_1(struct task_struct *p, struct rq *rq)
++{
++ p->boost_prio = MAX_PRIORITY_ADJ;
++}
++
++#ifdef CONFIG_SMP
++static void sched_task_ttwu(struct task_struct *p)
++{
++ if(this_rq()->clock_task - p->last_ran > sched_timeslice_ns)
++ boost_task(p);
++}
++#endif
++
++static void sched_task_deactivate(struct task_struct *p, struct rq *rq)
++{
++ if (rq_switch_time(rq) < boost_threshold(p))
++ boost_task(p);
++}
+diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
+index 50cbad89f7fa..fb703fd370fd 100644
+--- a/kernel/sched/cpufreq_schedutil.c
++++ b/kernel/sched/cpufreq_schedutil.c
+@@ -57,6 +57,13 @@ struct sugov_cpu {
+ unsigned long bw_dl;
+ unsigned long max;
+
++#ifdef CONFIG_SCHED_ALT
++ /* For genenal cpu load util */
++ s32 load_history;
++ u64 load_block;
++ u64 load_stamp;
++#endif
++
+ /* The field below is for single-CPU policies only: */
+ #ifdef CONFIG_NO_HZ_COMMON
+ unsigned long saved_idle_calls;
+@@ -171,6 +178,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
+ return cpufreq_driver_resolve_freq(policy, freq);
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ static void sugov_get_util(struct sugov_cpu *sg_cpu)
+ {
+ struct rq *rq = cpu_rq(sg_cpu->cpu);
+@@ -182,6 +190,55 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu)
+ FREQUENCY_UTIL, NULL);
+ }
+
++#else /* CONFIG_SCHED_ALT */
++
++#define SG_CPU_LOAD_HISTORY_BITS (sizeof(s32) * 8ULL)
++#define SG_CPU_UTIL_SHIFT (8)
++#define SG_CPU_LOAD_HISTORY_SHIFT (SG_CPU_LOAD_HISTORY_BITS - 1 - SG_CPU_UTIL_SHIFT)
++#define SG_CPU_LOAD_HISTORY_TO_UTIL(l) (((l) >> SG_CPU_LOAD_HISTORY_SHIFT) & 0xff)
++
++#define LOAD_BLOCK(t) ((t) >> 17)
++#define LOAD_HALF_BLOCK(t) ((t) >> 16)
++#define BLOCK_MASK(t) ((t) & ((0x01 << 18) - 1))
++#define LOAD_BLOCK_BIT(b) (1UL << (SG_CPU_LOAD_HISTORY_BITS - 1 - (b)))
++#define CURRENT_LOAD_BIT LOAD_BLOCK_BIT(0)
++
++static void sugov_get_util(struct sugov_cpu *sg_cpu)
++{
++ unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu);
++
++ sg_cpu->max = max;
++ sg_cpu->bw_dl = 0;
++ sg_cpu->util = SG_CPU_LOAD_HISTORY_TO_UTIL(sg_cpu->load_history) *
++ (max >> SG_CPU_UTIL_SHIFT);
++}
++
++static inline void sugov_cpu_load_update(struct sugov_cpu *sg_cpu, u64 time)
++{
++ u64 delta = min(LOAD_BLOCK(time) - LOAD_BLOCK(sg_cpu->load_stamp),
++ SG_CPU_LOAD_HISTORY_BITS - 1);
++ u64 prev = !!(sg_cpu->load_history & CURRENT_LOAD_BIT);
++ u64 curr = !!cpu_rq(sg_cpu->cpu)->nr_running;
++
++ if (delta) {
++ sg_cpu->load_history = sg_cpu->load_history >> delta;
++
++ if (delta <= SG_CPU_UTIL_SHIFT) {
++ sg_cpu->load_block += (~BLOCK_MASK(sg_cpu->load_stamp)) * prev;
++ if (!!LOAD_HALF_BLOCK(sg_cpu->load_block) ^ curr)
++ sg_cpu->load_history ^= LOAD_BLOCK_BIT(delta);
++ }
++
++ sg_cpu->load_block = BLOCK_MASK(time) * prev;
++ } else {
++ sg_cpu->load_block += (time - sg_cpu->load_stamp) * prev;
++ }
++ if (prev ^ curr)
++ sg_cpu->load_history ^= CURRENT_LOAD_BIT;
++ sg_cpu->load_stamp = time;
++}
++#endif /* CONFIG_SCHED_ALT */
++
+ /**
+ * sugov_iowait_reset() - Reset the IO boost status of a CPU.
+ * @sg_cpu: the sugov data for the CPU to boost
+@@ -322,13 +379,19 @@ static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
+ */
+ static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu)
+ {
++#ifndef CONFIG_SCHED_ALT
+ if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl)
+ sg_cpu->sg_policy->limits_changed = true;
++#endif
+ }
+
+ static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu,
+ u64 time, unsigned int flags)
+ {
++#ifdef CONFIG_SCHED_ALT
++ sugov_cpu_load_update(sg_cpu, time);
++#endif /* CONFIG_SCHED_ALT */
++
+ sugov_iowait_boost(sg_cpu, time, flags);
+ sg_cpu->last_update = time;
+
+@@ -446,6 +509,10 @@ sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
+
+ raw_spin_lock(&sg_policy->update_lock);
+
++#ifdef CONFIG_SCHED_ALT
++ sugov_cpu_load_update(sg_cpu, time);
++#endif /* CONFIG_SCHED_ALT */
++
+ sugov_iowait_boost(sg_cpu, time, flags);
+ sg_cpu->last_update = time;
+
+@@ -603,6 +670,7 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy)
+ }
+
+ ret = sched_setattr_nocheck(thread, &attr);
++
+ if (ret) {
+ kthread_stop(thread);
+ pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__);
+@@ -835,6 +903,7 @@ struct cpufreq_governor *cpufreq_default_governor(void)
+ cpufreq_governor_init(schedutil_gov);
+
+ #ifdef CONFIG_ENERGY_MODEL
++#ifndef CONFIG_SCHED_ALT
+ static void rebuild_sd_workfn(struct work_struct *work)
+ {
+ rebuild_sched_domains_energy();
+@@ -858,4 +927,10 @@ void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
+ }
+
+ }
++#else /* CONFIG_SCHED_ALT */
++void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
++ struct cpufreq_governor *old_gov)
++{
++}
++#endif
+ #endif
+diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
+index 5f611658eeab..631276f56ba0 100644
+--- a/kernel/sched/cputime.c
++++ b/kernel/sched/cputime.c
+@@ -123,7 +123,7 @@ void account_user_time(struct task_struct *p, u64 cputime)
+ p->utime += cputime;
+ account_group_user_time(p, cputime);
+
+- index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
++ index = task_running_nice(p) ? CPUTIME_NICE : CPUTIME_USER;
+
+ /* Add user time to cpustat. */
+ task_group_account_field(p, index, cputime);
+@@ -147,7 +147,7 @@ void account_guest_time(struct task_struct *p, u64 cputime)
+ p->gtime += cputime;
+
+ /* Add guest time to cpustat. */
+- if (task_nice(p) > 0) {
++ if (task_running_nice(p)) {
+ cpustat[CPUTIME_NICE] += cputime;
+ cpustat[CPUTIME_GUEST_NICE] += cputime;
+ } else {
+@@ -270,7 +270,7 @@ static inline u64 account_other_time(u64 max)
+ #ifdef CONFIG_64BIT
+ static inline u64 read_sum_exec_runtime(struct task_struct *t)
+ {
+- return t->se.sum_exec_runtime;
++ return tsk_seruntime(t);
+ }
+ #else
+ static u64 read_sum_exec_runtime(struct task_struct *t)
+@@ -280,7 +280,7 @@ static u64 read_sum_exec_runtime(struct task_struct *t)
+ struct rq *rq;
+
+ rq = task_rq_lock(t, &rf);
+- ns = t->se.sum_exec_runtime;
++ ns = tsk_seruntime(t);
+ task_rq_unlock(rq, t, &rf);
+
+ return ns;
+@@ -612,7 +612,7 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,
+ void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st)
+ {
+ struct task_cputime cputime = {
+- .sum_exec_runtime = p->se.sum_exec_runtime,
++ .sum_exec_runtime = tsk_seruntime(p),
+ };
+
+ task_cputime(p, &cputime.utime, &cputime.stime);
+diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
+index 7199e6f23789..bbdd227da3a4 100644
+--- a/kernel/sched/idle.c
++++ b/kernel/sched/idle.c
+@@ -397,6 +397,7 @@ void cpu_startup_entry(enum cpuhp_state state)
+ do_idle();
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ /*
+ * idle-task scheduling class.
+ */
+@@ -510,3 +511,4 @@ DEFINE_SCHED_CLASS(idle) = {
+ .switched_to = switched_to_idle,
+ .update_curr = update_curr_idle,
+ };
++#endif
+diff --git a/kernel/sched/pds.h b/kernel/sched/pds.h
+new file mode 100644
+index 000000000000..623908cf4380
+--- /dev/null
++++ b/kernel/sched/pds.h
+@@ -0,0 +1,9 @@
++#ifndef PDS_H
++#define PDS_H
++
++/* bits:
++ * RT(0-99), (Low prio adj range, nice width, high prio adj range) / 2, cpu idle task */
++#define SCHED_BITS (MAX_RT_PRIO + NICE_WIDTH / 2 + 1)
++#define IDLE_TASK_SCHED_PRIO (SCHED_BITS - 1)
++
++#endif
+diff --git a/kernel/sched/pds_imp.h b/kernel/sched/pds_imp.h
+new file mode 100644
+index 000000000000..335ce3a8e3ec
+--- /dev/null
++++ b/kernel/sched/pds_imp.h
+@@ -0,0 +1,279 @@
++#define ALT_SCHED_VERSION_MSG "sched/pds: PDS CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n"
++
++static const u64 user_prio2deadline[NICE_WIDTH] = {
++/* -20 */ 4194304, 4613734, 5075107, 5582617, 6140878,
++/* -15 */ 6754965, 7430461, 8173507, 8990857, 9889942,
++/* -10 */ 10878936, 11966829, 13163511, 14479862, 15927848,
++/* -5 */ 17520632, 19272695, 21199964, 23319960, 25651956,
++/* 0 */ 28217151, 31038866, 34142752, 37557027, 41312729,
++/* 5 */ 45444001, 49988401, 54987241, 60485965, 66534561,
++/* 10 */ 73188017, 80506818, 88557499, 97413248, 107154572,
++/* 15 */ 117870029, 129657031, 142622734, 156885007, 172573507
++};
++
++static const unsigned char dl_level_map[] = {
++/* 0 4 8 12 */
++ 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 18,
++/* 16 20 24 28 */
++ 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 17, 17, 17, 17, 17,
++/* 32 36 40 44 */
++ 17, 17, 17, 17, 16, 16, 16, 16, 16, 16, 16, 16, 15, 15, 15, 15,
++/* 48 52 56 60 */
++ 15, 15, 15, 14, 14, 14, 14, 14, 14, 13, 13, 13, 13, 12, 12, 12,
++/* 64 68 72 76 */
++ 12, 11, 11, 11, 10, 10, 10, 9, 9, 8, 7, 6, 5, 4, 3, 2,
++/* 80 84 88 92 */
++ 1, 0
++};
++
++/* DEFAULT_SCHED_PRIO:
++ * dl_level_map[(user_prio2deadline[39] - user_prio2deadline[0]) >> 21] =
++ * dl_level_map[68] =
++ * 10
++ */
++#define DEFAULT_SCHED_PRIO (MAX_RT_PRIO + 10)
++
++static inline int normal_prio(struct task_struct *p)
++{
++ if (task_has_rt_policy(p))
++ return MAX_RT_PRIO - 1 - p->rt_priority;
++
++ return MAX_RT_PRIO;
++}
++
++static inline int
++task_sched_prio(const struct task_struct *p, const struct rq *rq)
++{
++ size_t delta;
++
++ if (p == rq->idle)
++ return IDLE_TASK_SCHED_PRIO;
++
++ if (p->prio < MAX_RT_PRIO)
++ return p->prio;
++
++ delta = (rq->clock + user_prio2deadline[39] - p->deadline) >> 21;
++ delta = min((size_t)delta, ARRAY_SIZE(dl_level_map) - 1);
++
++ return MAX_RT_PRIO + dl_level_map[delta];
++}
++
++int task_running_nice(struct task_struct *p)
++{
++ return task_sched_prio(p, task_rq(p)) > DEFAULT_SCHED_PRIO;
++}
++
++static inline void update_task_priodl(struct task_struct *p)
++{
++ p->priodl = (((u64) (p->prio))<<56) | ((p->deadline)>>8);
++}
++
++static inline void requeue_task(struct task_struct *p, struct rq *rq);
++
++static inline void time_slice_expired(struct task_struct *p, struct rq *rq)
++{
++ /*printk(KERN_INFO "sched: time_slice_expired(%d) - %px\n", cpu_of(rq), p);*/
++ p->time_slice = sched_timeslice_ns;
++
++ if (p->prio >= MAX_RT_PRIO)
++ p->deadline = rq->clock +
++ user_prio2deadline[p->static_prio - MAX_RT_PRIO];
++ update_task_priodl(p);
++
++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p))
++ requeue_task(p, rq);
++}
++
++/*
++ * pds_skiplist_task_search -- search function used in PDS run queue skip list
++ * node insert operation.
++ * @it: iterator pointer to the node in the skip list
++ * @node: pointer to the skiplist_node to be inserted
++ *
++ * Returns true if key of @it is less or equal to key value of @node, otherwise
++ * false.
++ */
++static inline bool
++pds_skiplist_task_search(struct skiplist_node *it, struct skiplist_node *node)
++{
++ return (skiplist_entry(it, struct task_struct, sl_node)->priodl <=
++ skiplist_entry(node, struct task_struct, sl_node)->priodl);
++}
++
++/*
++ * Define the skip list insert function for PDS
++ */
++DEFINE_SKIPLIST_INSERT_FUNC(pds_skiplist_insert, pds_skiplist_task_search);
++
++/*
++ * Init the queue structure in rq
++ */
++static inline void sched_queue_init(struct rq *rq)
++{
++ INIT_SKIPLIST_NODE(&rq->sl_header);
++}
++
++/*
++ * Init idle task and put into queue structure of rq
++ * IMPORTANT: may be called multiple times for a single cpu
++ */
++static inline void sched_queue_init_idle(struct rq *rq, struct task_struct *idle)
++{
++ /*printk(KERN_INFO "sched: init(%d) - %px\n", cpu_of(rq), idle);*/
++ int default_prio = idle->prio;
++
++ idle->prio = MAX_PRIO;
++ idle->deadline = 0ULL;
++ update_task_priodl(idle);
++
++ INIT_SKIPLIST_NODE(&rq->sl_header);
++
++ idle->sl_node.level = idle->sl_level;
++ pds_skiplist_insert(&rq->sl_header, &idle->sl_node);
++
++ idle->prio = default_prio;
++}
++
++/*
++ * This routine assume that the idle task always in queue
++ */
++static inline struct task_struct *sched_rq_first_task(struct rq *rq)
++{
++ struct skiplist_node *node = rq->sl_header.next[0];
++
++ BUG_ON(node == &rq->sl_header);
++ return skiplist_entry(node, struct task_struct, sl_node);
++}
++
++static inline struct task_struct *
++sched_rq_next_task(struct task_struct *p, struct rq *rq)
++{
++ struct skiplist_node *next = p->sl_node.next[0];
++
++ BUG_ON(next == &rq->sl_header);
++ return skiplist_entry(next, struct task_struct, sl_node);
++}
++
++static inline unsigned long sched_queue_watermark(struct rq *rq)
++{
++ return task_sched_prio(sched_rq_first_task(rq), rq);
++}
++
++#define __SCHED_DEQUEUE_TASK(p, rq, flags, func) \
++ psi_dequeue(p, flags & DEQUEUE_SLEEP); \
++ sched_info_dequeued(rq, p); \
++ \
++ if (skiplist_del_init(&rq->sl_header, &p->sl_node)) { \
++ func; \
++ }
++
++#define __SCHED_ENQUEUE_TASK(p, rq, flags) \
++ sched_info_queued(rq, p); \
++ psi_enqueue(p, flags); \
++ \
++ p->sl_node.level = p->sl_level; \
++ pds_skiplist_insert(&rq->sl_header, &p->sl_node)
++
++/*
++ * Requeue a task @p to @rq
++ */
++#define __SCHED_REQUEUE_TASK(p, rq, func) \
++{\
++ bool b_first = skiplist_del_init(&rq->sl_header, &p->sl_node); \
++\
++ p->sl_node.level = p->sl_level; \
++ if (pds_skiplist_insert(&rq->sl_header, &p->sl_node) || b_first) { \
++ func; \
++ } \
++}
++
++static inline bool sched_task_need_requeue(struct task_struct *p, struct rq *rq)
++{
++ struct skiplist_node *node;
++
++ node = p->sl_node.prev[0];
++ if (node != &rq->sl_header &&
++ skiplist_entry(node, struct task_struct, sl_node)->priodl > p->priodl)
++ return true;
++
++ node = p->sl_node.next[0];
++ if (node != &rq->sl_header &&
++ skiplist_entry(node, struct task_struct, sl_node)->priodl < p->priodl)
++ return true;
++
++ return false;
++}
++
++/*
++ * pds_skiplist_random_level -- Returns a pseudo-random level number for skip
++ * list node which is used in PDS run queue.
++ *
++ * __ffs() is used to satisfy p = 0.5 between each levels, and there should be
++ * platform instruction(known as ctz/clz) for acceleration.
++ *
++ * The skiplist level for a task is populated when task is created and doesn't
++ * change in task's life time. When task is being inserted into run queue, this
++ * skiplist level is set to task's sl_node->level, the skiplist insert function
++ * may change it based on current level of the skip lsit.
++ */
++static inline int pds_skiplist_random_level(const struct task_struct *p)
++{
++ /*
++ * 1. Some architectures don't have better than microsecond resolution
++ * so mask out ~microseconds as a factor of the random seed for skiplist
++ * insertion.
++ * 2. Use address of task structure pointer as another factor of the
++ * random seed for task burst forking scenario.
++ */
++ unsigned long randseed = (task_rq(p)->clock ^ (unsigned long)p) >> 10;
++
++ randseed &= __GENMASK(NUM_SKIPLIST_LEVEL - 1, 0);
++ if (randseed)
++ return __ffs(randseed);
++
++ return (NUM_SKIPLIST_LEVEL - 1);
++}
++
++static void sched_task_fork(struct task_struct *p, struct rq *rq)
++{
++ p->sl_level = pds_skiplist_random_level(p);
++ if (p->prio >= MAX_RT_PRIO)
++ p->deadline = rq->clock +
++ user_prio2deadline[p->static_prio - MAX_RT_PRIO];
++ update_task_priodl(p);
++}
++
++/**
++ * task_prio - return the priority value of a given task.
++ * @p: the task in question.
++ *
++ * Return: The priority value as seen by users in /proc.
++ *
++ * sched policy return value kernel prio user prio/nice
++ *
++ * normal, batch, idle [0 ... 39] 100 0/[-20 ... 19]
++ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99]
++ */
++int task_prio(const struct task_struct *p)
++{
++ int ret;
++
++ if (p->prio < MAX_RT_PRIO)
++ return (p->prio - MAX_RT_PRIO);
++
++ preempt_disable();
++ ret = task_sched_prio(p, this_rq()) - MAX_RT_PRIO;
++ preempt_enable();
++
++ return ret;
++}
++
++static void do_sched_yield_type_1(struct task_struct *p, struct rq *rq)
++{
++ time_slice_expired(p, rq);
++}
++
++#ifdef CONFIG_SMP
++static void sched_task_ttwu(struct task_struct *p) {}
++#endif
++static void sched_task_deactivate(struct task_struct *p, struct rq *rq) {}
+diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
+index 2c613e1cff3a..0103b2a7201d 100644
+--- a/kernel/sched/pelt.c
++++ b/kernel/sched/pelt.c
+@@ -270,6 +270,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load)
+ WRITE_ONCE(sa->util_avg, sa->util_sum / divider);
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ /*
+ * sched_entity:
+ *
+@@ -387,8 +388,9 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
+
+ return 0;
+ }
++#endif
+
+-#ifdef CONFIG_SCHED_THERMAL_PRESSURE
++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT)
+ /*
+ * thermal:
+ *
+diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
+index 795e43e02afc..856163dac896 100644
+--- a/kernel/sched/pelt.h
++++ b/kernel/sched/pelt.h
+@@ -1,13 +1,15 @@
+ #ifdef CONFIG_SMP
+ #include "sched-pelt.h"
+
++#ifndef CONFIG_SCHED_ALT
+ int __update_load_avg_blocked_se(u64 now, struct sched_entity *se);
+ int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se);
+ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
+ int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
+ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
++#endif
+
+-#ifdef CONFIG_SCHED_THERMAL_PRESSURE
++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT)
+ int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity);
+
+ static inline u64 thermal_load_avg(struct rq *rq)
+@@ -42,6 +44,7 @@ static inline u32 get_pelt_divider(struct sched_avg *avg)
+ return LOAD_AVG_MAX - 1024 + avg->period_contrib;
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ /*
+ * When a task is dequeued, its estimated utilization should not be update if
+ * its util_avg has not been updated at least once.
+@@ -162,9 +165,11 @@ static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
+ return rq_clock_pelt(rq_of(cfs_rq));
+ }
+ #endif
++#endif /* CONFIG_SCHED_ALT */
+
+ #else
+
++#ifndef CONFIG_SCHED_ALT
+ static inline int
+ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
+ {
+@@ -182,6 +187,7 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
+ {
+ return 0;
+ }
++#endif
+
+ static inline int
+ update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
+index 10a1522b1e30..1a74a266340b 100644
+--- a/kernel/sched/sched.h
++++ b/kernel/sched/sched.h
+@@ -2,6 +2,10 @@
+ /*
+ * Scheduler internal types and methods:
+ */
++#ifdef CONFIG_SCHED_ALT
++#include "alt_sched.h"
++#else
++
+ #include <linux/sched.h>
+
+ #include <linux/sched/autogroup.h>
+@@ -2720,3 +2724,9 @@ static inline bool is_per_cpu_kthread(struct task_struct *p)
+
+ void swake_up_all_locked(struct swait_queue_head *q);
+ void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
++
++static inline int task_running_nice(struct task_struct *p)
++{
++ return (task_nice(p) > 0);
++}
++#endif /* !CONFIG_SCHED_ALT */
+diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
+index 750fb3c67eed..108422ebc7bf 100644
+--- a/kernel/sched/stats.c
++++ b/kernel/sched/stats.c
+@@ -22,8 +22,10 @@ static int show_schedstat(struct seq_file *seq, void *v)
+ } else {
+ struct rq *rq;
+ #ifdef CONFIG_SMP
++#ifndef CONFIG_SCHED_ALT
+ struct sched_domain *sd;
+ int dcount = 0;
++#endif
+ #endif
+ cpu = (unsigned long)(v - 2);
+ rq = cpu_rq(cpu);
+@@ -40,6 +42,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
+ seq_printf(seq, "\n");
+
+ #ifdef CONFIG_SMP
++#ifndef CONFIG_SCHED_ALT
+ /* domain-specific stats */
+ rcu_read_lock();
+ for_each_domain(cpu, sd) {
+@@ -68,6 +71,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
+ sd->ttwu_move_balance);
+ }
+ rcu_read_unlock();
++#endif
+ #endif
+ }
+ return 0;
+diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
+index 09d35044bd88..2c146b042b51 100644
+--- a/kernel/sched/topology.c
++++ b/kernel/sched/topology.c
+@@ -4,6 +4,7 @@
+ */
+ #include "sched.h"
+
++#ifndef CONFIG_SCHED_ALT
+ DEFINE_MUTEX(sched_domains_mutex);
+
+ /* Protected by sched_domains_mutex: */
+@@ -1241,8 +1242,10 @@ static void init_sched_groups_capacity(int cpu, struct sched_domain *sd)
+ */
+
+ static int default_relax_domain_level = -1;
++#endif /* CONFIG_SCHED_ALT */
+ int sched_domain_level_max;
+
++#ifndef CONFIG_SCHED_ALT
+ static int __init setup_relax_domain_level(char *str)
+ {
+ if (kstrtoint(str, 0, &default_relax_domain_level))
+@@ -1472,6 +1475,7 @@ sd_init(struct sched_domain_topology_level *tl,
+
+ return sd;
+ }
++#endif /* CONFIG_SCHED_ALT */
+
+ /*
+ * Topology list, bottom-up.
+@@ -1501,6 +1505,7 @@ void set_sched_topology(struct sched_domain_topology_level *tl)
+ sched_domain_topology = tl;
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ #ifdef CONFIG_NUMA
+
+ static const struct cpumask *sd_numa_mask(int cpu)
+@@ -2371,3 +2376,17 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
+ partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
+ mutex_unlock(&sched_domains_mutex);
+ }
++#else /* CONFIG_SCHED_ALT */
++void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
++ struct sched_domain_attr *dattr_new)
++{}
++
++#ifdef CONFIG_NUMA
++int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE;
++
++int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
++{
++ return best_mask_cpu(cpu, cpus);
++}
++#endif /* CONFIG_NUMA */
++#endif
+diff --git a/kernel/sysctl.c b/kernel/sysctl.c
+index 62fbd09b5dc1..19f9a6185db3 100644
+--- a/kernel/sysctl.c
++++ b/kernel/sysctl.c
+@@ -120,6 +120,10 @@ static unsigned long long_max = LONG_MAX;
+ static int one_hundred = 100;
+ static int two_hundred = 200;
+ static int one_thousand = 1000;
++#ifdef CONFIG_SCHED_ALT
++static int __maybe_unused zero = 0;
++extern int sched_yield_type;
++#endif
+ #ifdef CONFIG_PRINTK
+ static int ten_thousand = 10000;
+ #endif
+@@ -184,7 +188,7 @@ static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT;
+ int sysctl_legacy_va_layout;
+ #endif
+
+-#ifdef CONFIG_SCHED_DEBUG
++#if defined(CONFIG_SCHED_DEBUG) && !defined(CONFIG_SCHED_ALT)
+ static int min_sched_granularity_ns = 100000; /* 100 usecs */
+ static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
+ static int min_wakeup_granularity_ns; /* 0 usecs */
+@@ -1652,6 +1656,24 @@ int proc_do_static_key(struct ctl_table *table, int write,
+ }
+
+ static struct ctl_table kern_table[] = {
++#ifdef CONFIG_SCHED_ALT
++/* In ALT, only supported "sched_schedstats" */
++#ifdef CONFIG_SCHED_DEBUG
++#ifdef CONFIG_SMP
++#ifdef CONFIG_SCHEDSTATS
++ {
++ .procname = "sched_schedstats",
++ .data = NULL,
++ .maxlen = sizeof(unsigned int),
++ .mode = 0644,
++ .proc_handler = sysctl_schedstats,
++ .extra1 = SYSCTL_ZERO,
++ .extra2 = SYSCTL_ONE,
++ },
++#endif /* CONFIG_SCHEDSTATS */
++#endif /* CONFIG_SMP */
++#endif /* CONFIG_SCHED_DEBUG */
++#else /* !CONFIG_SCHED_ALT */
+ {
+ .procname = "sched_child_runs_first",
+ .data = &sysctl_sched_child_runs_first,
+@@ -1854,6 +1876,7 @@ static struct ctl_table kern_table[] = {
+ .extra2 = SYSCTL_ONE,
+ },
+ #endif
++#endif /* !CONFIG_SCHED_ALT */
+ #ifdef CONFIG_PROVE_LOCKING
+ {
+ .procname = "prove_locking",
+@@ -2430,6 +2453,17 @@ static struct ctl_table kern_table[] = {
+ .proc_handler = proc_dointvec,
+ },
+ #endif
++#ifdef CONFIG_SCHED_ALT
++ {
++ .procname = "yield_type",
++ .data = &sched_yield_type,
++ .maxlen = sizeof (int),
++ .mode = 0644,
++ .proc_handler = &proc_dointvec_minmax,
++ .extra1 = &zero,
++ .extra2 = &two,
++ },
++#endif
+ #if defined(CONFIG_S390) && defined(CONFIG_SMP)
+ {
+ .procname = "spin_retry",
+diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
+index 5c9d968187ae..fe47db46303c 100644
+--- a/kernel/time/hrtimer.c
++++ b/kernel/time/hrtimer.c
+@@ -1940,8 +1940,10 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
+ int ret = 0;
+ u64 slack;
+
++#ifndef CONFIG_SCHED_ALT
+ slack = current->timer_slack_ns;
+ if (dl_task(current) || rt_task(current))
++#endif
+ slack = 0;
+
+ hrtimer_init_sleeper_on_stack(&t, clockid, mode);
+diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
+index 9abe15255bc4..691db8192ddb 100644
+--- a/kernel/time/posix-cpu-timers.c
++++ b/kernel/time/posix-cpu-timers.c
+@@ -216,7 +216,7 @@ static void task_sample_cputime(struct task_struct *p, u64 *samples)
+ u64 stime, utime;
+
+ task_cputime(p, &utime, &stime);
+- store_samples(samples, stime, utime, p->se.sum_exec_runtime);
++ store_samples(samples, stime, utime, tsk_seruntime(p));
+ }
+
+ static void proc_sample_cputime_atomic(struct task_cputime_atomic *at,
+@@ -801,6 +801,7 @@ static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples,
+ }
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ static inline void check_dl_overrun(struct task_struct *tsk)
+ {
+ if (tsk->dl.dl_overrun) {
+@@ -808,6 +809,7 @@ static inline void check_dl_overrun(struct task_struct *tsk)
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ }
+ }
++#endif
+
+ static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard)
+ {
+@@ -835,8 +837,10 @@ static void check_thread_timers(struct task_struct *tsk,
+ u64 samples[CPUCLOCK_MAX];
+ unsigned long soft;
+
++#ifndef CONFIG_SCHED_ALT
+ if (dl_task(tsk))
+ check_dl_overrun(tsk);
++#endif
+
+ if (expiry_cache_is_inactive(pct))
+ return;
+@@ -850,7 +854,7 @@ static void check_thread_timers(struct task_struct *tsk,
+ soft = task_rlimit(tsk, RLIMIT_RTTIME);
+ if (soft != RLIM_INFINITY) {
+ /* Task RT timeout is accounted in jiffies. RTTIME is usec */
+- unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ);
++ unsigned long rttime = tsk_rttimeout(tsk) * (USEC_PER_SEC / HZ);
+ unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME);
+
+ /* At the hard limit, send SIGKILL. No further action. */
+@@ -1086,8 +1090,10 @@ static inline bool fastpath_timer_check(struct task_struct *tsk)
+ return true;
+ }
+
++#ifndef CONFIG_SCHED_ALT
+ if (dl_task(tsk) && tsk->dl.dl_overrun)
+ return true;
++#endif
+
+ return false;
+ }
+diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
+index 73ef12092250..24bf8ef1249a 100644
+--- a/kernel/trace/trace_selftest.c
++++ b/kernel/trace/trace_selftest.c
+@@ -1052,10 +1052,15 @@ static int trace_wakeup_test_thread(void *data)
+ {
+ /* Make this a -deadline thread */
+ static const struct sched_attr attr = {
++#ifdef CONFIG_SCHED_ALT
++ /* No deadline on BMQ/PDS, use RR */
++ .sched_policy = SCHED_RR,
++#else
+ .sched_policy = SCHED_DEADLINE,
+ .sched_runtime = 100000ULL,
+ .sched_deadline = 10000000ULL,
+ .sched_period = 10000000ULL
++#endif
+ };
+ struct wakeup_test_data *x = data;
+
diff --git a/5021_BMQ-and-PDS-gentoo-defaults-v5.12-r0.patch b/5021_BMQ-and-PDS-gentoo-defaults-v5.12-r0.patch
new file mode 100644
index 0000000..d449eec
--- /dev/null
+++ b/5021_BMQ-and-PDS-gentoo-defaults-v5.12-r0.patch
@@ -0,0 +1,13 @@
+--- a/init/Kconfig 2021-04-27 07:38:30.556467045 -0400
++++ b/init/Kconfig 2021-04-27 07:39:32.956412800 -0400
+@@ -780,8 +780,9 @@ config GENERIC_SCHED_CLOCK
+ menu "Scheduler features"
+
+ menuconfig SCHED_ALT
++ depends on X86_64
+ bool "Alternative CPU Schedulers"
+- default y
++ default n
+ help
+ This feature enable alternative CPU scheduler"
+
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