Limiting CPU resources of a cgroup (how do I) HELP REQUESTED

Limiting CPU resources of a cgroup (how do I) HELP REQUESTED

[Vecu BOSSEUR]

Dear Friends or Foes ;-)


It is quite some time now that I first tried to find an adequate
solution to my problem; none managed to get me right yet :=-(

Basically, I would like to limit CPU resource usage (i.e. ~= time
share) allocated to a said cgroup to let's say 30% of the machine
processing power, or 30 % of time.
( SMP and HyperThreading technologies will change the interpretation
of that goal; regardless, please read on. )

I am in the very need to throttle some cgroup's CPU usage, regardless
the overall machine CPU utilisation. I mean that I need to cap the
processing power dedicated and allowed to some cgroup, whether the
CPU(s) is(are) otherwise IDLE or BUSY (with respect to other tasks or
groups).

Any hint on how to accomplish this?

All that I happend to do was to create a renice-boosted daemon that
alternately froze then unfroze the said cgroup (using a calculated
time ratio between running/frozen states) to keep the cgroup's CPU
usage under control.

You can ea

Re: Limiting CPU resources of a cgroup (how do I) HELP REQUESTED

[Udayan Bapat]

Unless, I am mistaken cgroup does not provide max guarantee. It can be used to provide min guarantee by setting CPU.shares value.

Besides, what is the use case where you would want to limit the usage even when other threads/cores are idle? Wouldn't you want to give 100 percent to finish your task earlier than giving say 30 percent only?


On Aug 8, 2012, at 8:24 AM, Vecu BOSSEUR <vecu.bosseur-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> Dear Friends or Foes ;-)
> 
> 
> It is quite some time now that I first tried to find an adequate
> solution to my problem; none managed to get me right yet :=-(
> 
> Basically, I would like to limit CPU resource usage (i.e. ~= time
> share) allocated to a said cgroup to let's say 30% of the machine
> processing power, or 30 % of time.
> ( SMP and HyperThreading technologies will change the interpretation
> of that goal; regardless, please read on. )
> 
> I am in the very need to throttle some cgroup's CPU usage, regardless
> the overall machine CPU utilisation. I mean that I need to cap the
> processing power dedicated and allowed to some cgroup, whether the
> CPU(s) is(are) otherwise IDLE or BUSY (with respect to other tasks or
> groups).
> 
> Any hint on how to accomplish this?
> 
> All that I happend to do was to create a renice-boosted daemon that
> alternately froze then unfroze the said cgroup (using a calculated
> time ratio between running/frozen states) to keep the cgroup's CPU
> usage under control.
> 
> You can ea
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Re: Limiting CPU resources of a cgroup (how do I) HELP REQUESTED

[Li Zefan]

On 2012/8/9 21:11, Udayan Bapat wrote:
> Unless, I am mistaken cgroup does not provide max guarantee. It can be used to provide min guarantee by setting CPU.shares value.

Yes it does, by setting cpu.cfs_quota_us and cpu.cfs_period_us.

> 
> Besides, what is the use case where you would want to limit the usage even when other threads/cores are idle? Wouldn't you want to give 100 percent to finish your task earlier than giving say 30 percent only?
> 
> 
> On Aug 8, 2012, at 8:24 AM, Vecu BOSSEUR <vecu.bosseur-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> 
>> Dear Friends or Foes ;-)
>>
>>
>> It is quite some time now that I first tried to find an adequate
>> solution to my problem; none managed to get me right yet :=-(
>>
>> Basically, I would like to limit CPU resource usage (i.e. ~= time
>> share) allocated to a said cgroup to let's say 30% of the machine
>> processing power, or 30 % of time.
>> ( SMP and HyperThreading technologies will change the interpretation
>> of that goal; regardless, please read on. )
>>
>> I am in the very need to throttle some cgroup's CPU usage, regardless
>> the overall machine CPU utilisation. I mean that I need to cap the
>> processing power dedicated and allowed to some cgroup, whether the
>> CPU(s) is(are) otherwise IDLE or BUSY (with respect to other tasks or
>> groups).
>>
>> Any hint on how to accomplish this?
>>
>> All that I happend to do was to create a renice-boosted daemon that
>> alternately froze then unfroze the said cgroup (using a calculated
>> time ratio between running/frozen states) to keep the cgroup's CPU
>> usage under control.
>>
>> You can ea