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Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg

From Vincent Guittot <vincent.guittot@linaro.org>
Newsgroups linux.kernel
Subject Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg
Date 2017-05-04 21:10 +0200
Message-ID <tDuiu-7H9-9@gated-at.bofh.it> (permalink)
References (6 earlier) <tCZRn-41a-1@gated-at.bofh.it> <tD2md-5RN-11@gated-at.bofh.it> <tDajL-2yX-5@gated-at.bofh.it> <tDkj8-Vp-3@gated-at.bofh.it> <tDt34-6JH-17@gated-at.bofh.it>
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Hi Tejun,

On 4 May 2017 at 19:43, Tejun Heo <tj@kernel.org> wrote:
> Hello,
>
> On Thu, May 04, 2017 at 10:19:46AM +0200, Vincent Guittot wrote:
>> > schbench inside a cgroup and have some base load, it is actually
>> > expected to show worse latency.  You need to give higher weight to the
>> > cgroup matching the number of active threads (to be accruate, scaled
>> > by duty cycle but shouldn't matter too much in practice).
>>
>> I don't have to change anything cgroup weight with mainline to get
>> good number which means that the base load which is quite close to
>> null, is probably not the problem
>
> So, while that *could* be the case, it could also be the baseline
> incorrectly favoring the nested cfs_rqs over other tasks because of
> the nested runnables being inflated with blocked load avgs.  I think
> it'd be a good idea to test with matching weight to put things on the
> even ground.

In the trace i have uploaded, you will see that regressions happen
whereas there is no other runnable threads around so it's not a matter
of background activities that disturbs schbench

Thanks
Vincent

>
> Thanks.
>
> --
> tejun

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Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-04-26 20:20 +0200
  Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-04-27 01:00 +0200
    Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-04-27 10:30 +0200
      Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-04-28 22:40 +0200
        Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-04-28 22:40 +0200
        Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Peter Zijlstra <peterz@infradead.org> - 2017-05-01 18:00 +0200
          Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-05-03 00:10 +0200
        Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-05-02 09:20 +0200
          Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-05-02 15:30 +0200
            Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-05-03 00:40 +0200
          Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-05-03 00:00 +0200
            Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-05-03 09:40 +0200
              Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Peter Zijlstra <peterz@infradead.org> - 2017-05-03 11:40 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-05-03 12:40 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Peter Zijlstra <peterz@infradead.org> - 2017-05-03 15:20 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-05-03 23:50 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-05-04 10:30 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-05-04 19:50 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Vincent Guittot <vincent.guittot@linaro.org> - 2017-05-04 21:10 +0200
                Re: [PATCH 2/2] sched/fair: Always propagate runnable_load_avg Tejun Heo <tj@kernel.org> - 2017-05-04 21:10 +0200

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