[gentoo-user] are cgroups automatic ?

[gentoo-user] are cgroups automatic ?

[Philip Webb]

I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
There's nothing in the docs in  /usr/src/linux
& a search via 'make menuconfig' shows nothing suggestive.
Does the kernel automatically set them up once they're enabled
or does the user have to do something to define them ? -- anyone know ?

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

[gentoo-user] are cgroups automatic ?

[Philip Webb]

I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
There's nothing in the docs in  /usr/src/linux
& a search via 'make menuconfig' shows nothing suggestive.
Does the kernel automatically set them up once they're enabled
or does the user have to do something to define them ? -- anyone know ?

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca

Re: [gentoo-user] are cgroups automatic ?

[Bill Longman]

On 04/11/2011 08:13 AM, Philip Webb wrote:
> I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
> There's nothing in the docs in  /usr/src/linux
> & a search via 'make menuconfig' shows nothing suggestive.
> Does the kernel automatically set them up once they're enabled
> or does the user have to do something to define them ? -- anyone know ?
> 

Are you sure there's no documentation?

/usr/src/linux/Documentation
$ grep -il cgroup */*.txt
accounting/cgroupstats.txt
block/cfq-iosched.txt
cgroups/blkio-controller.txt
cgroups/cgroups.txt
cgroups/cpuacct.txt
cgroups/cpusets.txt
cgroups/devices.txt
cgroups/freezer-subsystem.txt
cgroups/memcg_test.txt
cgroups/memory.txt
cgroups/resource_counter.txt
filesystems/tmpfs.txt
scheduler/sched-design-CFS.txt
scheduler/sched-rt-group.txt
sysctl/vm.txt
vm/hwpoison.txt
vm/numa_memory_policy.txt
vm/unevictable-lru.txt

Re: [gentoo-user] are cgroups automatic ?

[Florian Philipp]

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Am 11.04.2011 17:13, schrieb Philip Webb:
> I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
> There's nothing in the docs in  /usr/src/linux
> & a search via 'make menuconfig' shows nothing suggestive.
> Does the kernel automatically set them up once they're enabled
> or does the user have to do something to define them ? -- anyone know ?
> 

I haven't tried 2.6.38 yet but I'm one of the authors of
http://en.gentoo-wiki.com/wiki/Improve_responsiveness_with_cgroups

I guess you can follow that guide (except that step about adding lines
to ~/.bashrc which is supposedly obsolete in 2.6.38). Then you can see
for yourself how the kernel arranges your processes in cgroups.

Your cgroup mount point should contain directories (different groups)
and in each directory there is a "tasks" file containing process ids of
the associated tasks.

While you are at it, you could update the information on the wiki. Any
help there is appreciated. :)

Regards,
Florian Philipp


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Re: [gentoo-user] are cgroups automatic ?

[dong l]

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You can dmesg|grep cgroup to see it works..
Sounds like
rquiss@Karata-Laptop ~ $ dmesg|grep cgroup
Initializing cgroup subsys cpuset
Initializing cgroup subsys cpu
allocated 41943040 bytes of page_cgroup
please try 'cgroup_disable=memory' option if you don't want memory cgroups
Initializing cgroup subsys ns
Initializing cgroup subsys cpuacct
Initializing cgroup subsys memory
Initializing cgroup subsys devices
Initializing cgroup subsys freezer
Initializing cgroup subsys blkio


2011/4/11 Philip Webb <purslow@ca.inter.net>

> I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
> There's nothing in the docs in  /usr/src/linux
> & a search via 'make menuconfig' shows nothing suggestive.
> Does the kernel automatically set them up once they're enabled
> or does the user have to do something to define them ? -- anyone know ?
>
> --
> ========================,,============================================
> SUPPORT     ___________//___,   Philip Webb
> ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
> TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca
>
>
>

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Re: [gentoo-user] are cgroups automatic ?

[Paul Hartman]

On Mon, Apr 11, 2011 at 10:13 AM, Philip Webb <purslow@ca.inter.net> wrote:
> I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
> There's nothing in the docs in  /usr/src/linux
> & a search via 'make menuconfig' shows nothing suggestive.
> Does the kernel automatically set them up once they're enabled
> or does the user have to do something to define them ? -- anyone know ?

AFAIK if you use 2.6.38 and see
/proc/sys/kernel/sched_autogroup_enabled = 1 then it should be active
and you don't need to do anything else special. But I could be wrong.

Re: [gentoo-user] are cgroups automatic ?

[Philip Webb]

110411 Bill Longman wrote:
> On 04/11/2011 08:13 AM, Philip Webb wrote:
>> I have enabled cgroups in kernel 2.6.38 , but am not sure how they work.
>> There's nothing in the docs in  /usr/src/linux
> Are you sure there's no documentation?

[long list snipped]

(red face) Yes there is.  And thanks to the others who had suggestions.
Now I can explore the topic at leisure.

-- 
========================,,============================================
SUPPORT     ___________//___,   Philip Webb
ELECTRIC   /] [] [] [] [] []|   Cities Centre, University of Toronto
TRANSIT    `-O----------O---'   purslowatchassdotutorontodotca