[gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Dale]

Howdy,

As most know, I use my puter to watch TV.  Most of the time, it works
fine.  On this new rig tho, it does something my much slower old rig
didn't do.  When I need to copy files from one set of drives to another,
the video stutters a bit.  Sometimes it will stop for several seconds
and it is annoying.  I'm thinking ionice might help with this but there
could also be a option in the kernel that would help as well.  There may
even be another way to make it not do this. 

Would setting ionice somehow for smplayer and its child processes work? 
Should I try to set ionice within Dolphin, what I usually use to copy
files over, to make it a lower priority.  I'd think setting one program
would be easier but maybe not.  Is there a better way that someone knows
of that I don't know about?  Kernel option maybe??

Ideas on best way to correct this?  If you need info, let me know.  I
can attach the kernel config or grep for certain options if needed. 

Thanks. 

Dale

:-)  :-)

Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Michael]

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On Wednesday, 23 July 2025 08:18:04 British Summer Time Dale wrote:
> Howdy,
> 
> As most know, I use my puter to watch TV.  Most of the time, it works
> fine.  On this new rig tho, it does something my much slower old rig
> didn't do.  When I need to copy files from one set of drives to another,
> the video stutters a bit.  Sometimes it will stop for several seconds
> and it is annoying.  I'm thinking ionice might help with this but there
> could also be a option in the kernel that would help as well.  There may
> even be another way to make it not do this. 
> 
> Would setting ionice somehow for smplayer and its child processes work? 
> Should I try to set ionice within Dolphin, what I usually use to copy
> files over, to make it a lower priority.  I'd think setting one program
> would be easier but maybe not.  Is there a better way that someone knows
> of that I don't know about?  Kernel option maybe??
> 
> Ideas on best way to correct this?  If you need info, let me know.  I
> can attach the kernel config or grep for certain options if needed. 
> 
> Thanks. 
> 
> Dale
> 
> :-)  :-)

In the first instance you should set a suitable scheduler for your drive(s).  
I understand with SSD the 'Deadline' is appropriate, but at least for spinning 
drives you should give BFQ a try.  You can red about BFQ here:

Documentation/block/bfq-iosched.rst 


If you prefer, you can even switch the IO scheduler in real time while 
monitoring performance, to verify which IO scheduler works best for your use 
case:

Documentation/block/switching-sched.rst


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Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Dale]

Michael wrote:
> On Wednesday, 23 July 2025 08:18:04 British Summer Time Dale wrote:
>> Howdy,
>>
>> As most know, I use my puter to watch TV.  Most of the time, it works
>> fine.  On this new rig tho, it does something my much slower old rig
>> didn't do.  When I need to copy files from one set of drives to another,
>> the video stutters a bit.  Sometimes it will stop for several seconds
>> and it is annoying.  I'm thinking ionice might help with this but there
>> could also be a option in the kernel that would help as well.  There may
>> even be another way to make it not do this. 
>>
>> Would setting ionice somehow for smplayer and its child processes work? 
>> Should I try to set ionice within Dolphin, what I usually use to copy
>> files over, to make it a lower priority.  I'd think setting one program
>> would be easier but maybe not.  Is there a better way that someone knows
>> of that I don't know about?  Kernel option maybe??
>>
>> Ideas on best way to correct this?  If you need info, let me know.  I
>> can attach the kernel config or grep for certain options if needed. 
>>
>> Thanks. 
>>
>> Dale
>>
>> :-)  :-)
> In the first instance you should set a suitable scheduler for your drive(s).  
> I understand with SSD the 'Deadline' is appropriate, but at least for spinning 
> drives you should give BFQ a try.  You can red about BFQ here:
>
> Documentation/block/bfq-iosched.rst 
>
>
> If you prefer, you can even switch the IO scheduler in real time while 
> monitoring performance, to verify which IO scheduler works best for your use 
> case:
>
> Documentation/block/switching-sched.rst
>


Read the top part of the text file.  That sounds like it should help. 
It sort of gives priority to IO that needs it.  While my OS is on a m.2
stick, the data that is giving me trouble is on spinning rust.  It's
those 50TB or so sets of drives.  Usually I'm copying from one set to
the other.  I might add, there is also other data being accessed as
well.  Some of it reading, smaller amount writing, usually.  It's
torrent stuff on one set of drives. 

I added BFQ to the kernel config and rebuilt.  I just need to reboot
now.  Watching a good show so I'll have to do that later.  Open to other
ideas as well.  This may be enough but wouldn't mind adjusting other
things that might make BFQ work even better or work along side it. 

Thanks much. 

Dale

:-)  :-) 

P. S.  Still not sure on email thing.  I want to but it sounds like a
hair puller.  :/ 

Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Dale]

Dale wrote:
> Michael wrote:
>> On Wednesday, 23 July 2025 08:18:04 British Summer Time Dale wrote:
>>> Howdy,
>>>
>>> As most know, I use my puter to watch TV.  Most of the time, it works
>>> fine.  On this new rig tho, it does something my much slower old rig
>>> didn't do.  When I need to copy files from one set of drives to another,
>>> the video stutters a bit.  Sometimes it will stop for several seconds
>>> and it is annoying.  I'm thinking ionice might help with this but there
>>> could also be a option in the kernel that would help as well.  There may
>>> even be another way to make it not do this. 
>>>
>>> Would setting ionice somehow for smplayer and its child processes work? 
>>> Should I try to set ionice within Dolphin, what I usually use to copy
>>> files over, to make it a lower priority.  I'd think setting one program
>>> would be easier but maybe not.  Is there a better way that someone knows
>>> of that I don't know about?  Kernel option maybe??
>>>
>>> Ideas on best way to correct this?  If you need info, let me know.  I
>>> can attach the kernel config or grep for certain options if needed. 
>>>
>>> Thanks. 
>>>
>>> Dale
>>>
>>> :-)  :-)
>> In the first instance you should set a suitable scheduler for your drive(s).  
>> I understand with SSD the 'Deadline' is appropriate, but at least for spinning 
>> drives you should give BFQ a try.  You can red about BFQ here:
>>
>> Documentation/block/bfq-iosched.rst 
>>
>>
>> If you prefer, you can even switch the IO scheduler in real time while 
>> monitoring performance, to verify which IO scheduler works best for your use 
>> case:
>>
>> Documentation/block/switching-sched.rst
>>
>
> Read the top part of the text file.  That sounds like it should help. 
> It sort of gives priority to IO that needs it.  While my OS is on a m.2
> stick, the data that is giving me trouble is on spinning rust.  It's
> those 50TB or so sets of drives.  Usually I'm copying from one set to
> the other.  I might add, there is also other data being accessed as
> well.  Some of it reading, smaller amount writing, usually.  It's
> torrent stuff on one set of drives. 
>
> I added BFQ to the kernel config and rebuilt.  I just need to reboot
> now.  Watching a good show so I'll have to do that later.  Open to other
> ideas as well.  This may be enough but wouldn't mind adjusting other
> things that might make BFQ work even better or work along side it. 
>
> Thanks much. 
>
> Dale
>
> :-)  :-) 
>
> P. S.  Still not sure on email thing.  I want to but it sounds like a
> hair puller.  :/ 
>

I wanted to update in case someone else is doing a search and runs up on
this thread.  I rebooted the new kernel and the BFQ setting is doing a
GREAT job.  I've copied several GBs of data since the change and my
videos play like a champ.  I've yet to see a single stutter or pause. 

Also, since I have several drives on LVM as one large file system, BFQ
has to be enabled for each drive.  There is three drives in two sets,
totaling around 50TBs for each set.  I had to enable BFQ for six
drives.  I also enabled BFQ for my drive that has /home on it.  From my
understanding, this should not be used on SSD type drives. 

So, if anyone has problems with video/audio while copying or moving data
from file system to file system, BFQ is a good thing to try.  It will
slow the copy process a little but it is worth it and it isn't much.

I knew there had to be a way to fix this and that someone on this list
would know how.  :-D 

Dale

:-)  :-) 

Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Peter Humphrey]

On Wednesday, 30 July 2025 18:25:00 British Summer Time Dale wrote:

> I rebooted the new kernel and the BFQ setting is doing a GREAT job.  I've
> copied several GBs of data since the change and my videos play like a
> champ.  I've yet to see a single stutter or pause. 

Have you selected either of the other schedulers as well?

-- 
Regards,
Peter.

Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Dale]

Peter Humphrey wrote:
> On Wednesday, 30 July 2025 18:25:00 British Summer Time Dale wrote:
>
>> I rebooted the new kernel and the BFQ setting is doing a GREAT job.  I've
>> copied several GBs of data since the change and my videos play like a
>> champ.  I've yet to see a single stutter or pause. 
> Have you selected either of the other schedulers as well?
>


From my understanding, you can only select one at a time.  So far, this
is working wonderfully.  A lot better than the previous one.  What
scheduler ones uses depends on what one needs.  For some applications,
others may work better.  For what I need, BFQ is awesome. 

Can one use more than one at a time?

Dale

:-)  :-) 

Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Michael]

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On Thursday, 31 July 2025 12:25:01 British Summer Time Dale wrote:
> Peter Humphrey wrote:
> > On Wednesday, 30 July 2025 18:25:00 British Summer Time Dale wrote:
> >> I rebooted the new kernel and the BFQ setting is doing a GREAT job.  I've
> >> copied several GBs of data since the change and my videos play like a
> >> champ.  I've yet to see a single stutter or pause.
> > 
> > Have you selected either of the other schedulers as well?
> 
> From my understanding, you can only select one at a time.  So far, this
> is working wonderfully.  A lot better than the previous one.  What
> scheduler ones uses depends on what one needs.  For some applications,
> others may work better.  For what I need, BFQ is awesome. 
> 
> Can one use more than one at a time?
> 
> Dale
> 
> :-)  :-) 

With more than one scheduler trying to manage the IO data queues on the 
device, which scheduler will win the fight?  The scheduler which messes up the 
others' queues faster?  LOL!  :-)

On multi-queue SSDs the difference between IO schedulers is small, so setting 
it to none (noop) removes any pointless kernel load.  However, some have 
reported mq-deadline performed slightly better on their gear.

A quick test will prove what scheduler suits best each use case.

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[gentoo-user] Re: Video sometimes stuttering. Need help with ionice, maybe?

[Holger Hoffstätte]

On Thu, 31 Jul 2025 14:22:56 +0100, Michael wrote:

> On multi-queue SSDs the difference between IO schedulers is small

https://dl.acm.org/doi/abs/10.1145/3629526.3645053
 
Nothing here is quick or easy.

Re: [gentoo-user] Re: Video sometimes stuttering. Need help with ionice, maybe?

[Michael]

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On Thursday, 31 July 2025 15:12:09 British Summer Time Holger Hoffstätte 
wrote:
> On Thu, 31 Jul 2025 14:22:56 +0100, Michael wrote:
> > On multi-queue SSDs the difference between IO schedulers is small
> 
> https://dl.acm.org/doi/abs/10.1145/3629526.3645053
> 
> Nothing here is quick or easy.

Quite so.  Developing a standardised test methodology for SSD drives in 
datacenters and having to account for many variables is a rather involved 
process.  However, running some quick tests with different schedulers on your 
PC to see if you notice a difference in your desired workload is a simpler 
affair.

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Re: [gentoo-user] Video sometimes stuttering. Need help with ionice, maybe?

[Dale]

Michael wrote:
> On Thursday, 31 July 2025 12:25:01 British Summer Time Dale wrote:
>> Peter Humphrey wrote:
>>> On Wednesday, 30 July 2025 18:25:00 British Summer Time Dale wrote:
>>>> I rebooted the new kernel and the BFQ setting is doing a GREAT job.  I've
>>>> copied several GBs of data since the change and my videos play like a
>>>> champ.  I've yet to see a single stutter or pause.
>>> Have you selected either of the other schedulers as well?
>> From my understanding, you can only select one at a time.  So far, this
>> is working wonderfully.  A lot better than the previous one.  What
>> scheduler ones uses depends on what one needs.  For some applications,
>> others may work better.  For what I need, BFQ is awesome. 
>>
>> Can one use more than one at a time?
>>
>> Dale
>>
>> :-)  :-) 
> With more than one scheduler trying to manage the IO data queues on the 
> device, which scheduler will win the fight?  The scheduler which messes up the 
> others' queues faster?  LOL!  :-)
>
> On multi-queue SSDs the difference between IO schedulers is small, so setting 
> it to none (noop) removes any pointless kernel load.  However, some have 
> reported mq-deadline performed slightly better on their gear.
>
> A quick test will prove what scheduler suits best each use case.


That was my thinking.  I'm trying to think of a reason why a person
would want to use two different ones anyway.  As you point out, one is
going to fight the other.  It's likely best to pick the one that works
best for the situation instead of trying to apply two or more and end up
with a nasty fight.  May not lose data but could upset a hard drive wear
and tear wise. 

Right now, BFQ is doing great.  I see no reason to switch to anything
else.  From what I've read, and seen in a couple videos, BFQ is the best
option for what I need.  I'll share video links below. 

You know, my rig and the software I have installed, it has gave me a
awesome system.  I'm thinking of upgrading the CPU tho.  I have a AMD
Ryzen 7 5800X 8-Core CPU right now.  Looking at a 5950X 16 core one. 
May be a year off yet tho.  I'm not sure how to deal with gkrellm tho. 
It already goes from top to bottom of my screen.  Additional cores is
going to make it to tall.  May have to run more than one gkrellm
somehow.  CPU cores, processes and sensor info on one and drive data on
another instance.  I gotta think on that. 

Video links. 

https://www.youtube.com/watch?v=J-e7LnJblm8  Demo of the performance of
the bfq disk I/O scheduler on a hard disk

https://www.youtube.com/watch?v=KhZl9LjCKuU  BFQ back in action

and

https://www.youtube.com/watch?v=1cjZeaCXIyM  BFQ-v7r6 versus CFQ,
DEADLINE and NOOP on an SSD

Dale

:-)  :-)