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Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and SPECjvm2008 benchmarks against 4.6 kernel

From Jirka Hladky <jhladky@redhat.com>
Newsgroups linux.kernel
Subject Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and SPECjvm2008 benchmarks against 4.6 kernel
Date 2016-06-24 14:10 +0200
Message-ID <rNy5P-7Tc-3@gated-at.bofh.it> (permalink)
References (2 earlier) <rKOA9-69f-9@gated-at.bofh.it> <rNhHH-5Aq-13@gated-at.bofh.it> <rNhRn-5Ej-5@gated-at.bofh.it> <rNu2d-5cW-7@gated-at.bofh.it> <rNy5P-7Tc-5@gated-at.bofh.it>
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Thank you Peter!

Should I apply it to v4.7-rc4 ?

Jirka

On Fri, Jun 24, 2016 at 2:02 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Jun 24, 2016 at 09:44:41AM +0200, Jirka Hladky wrote:
>> Hi Peter,
>>
>> thanks a lot for looking into it!
>>
>> I have tried to disable autogroups
>>
>> sysctl -w kernel.sched_autogroup_enabled=0
>>
>> and I can confirm that performance is then back at level as in 4.6 kernel.
>
> So unless the heat has made me do really silly things, the below seems
> to cure things. Could you please verify?
>
>
> ---
>  kernel/sched/fair.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 22d64b3f5876..d4f6fb2f3057 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -2484,7 +2484,7 @@ static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
>          */
>         tg_weight = atomic_long_read(&tg->load_avg);
>         tg_weight -= cfs_rq->tg_load_avg_contrib;
> -       tg_weight += cfs_rq->load.weight;
> +       tg_weight += cfs_rq->avg.load_avg;
>
>         return tg_weight;
>  }
> @@ -2494,7 +2494,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
>         long tg_weight, load, shares;
>
>         tg_weight = calc_tg_weight(tg, cfs_rq);
> -       load = cfs_rq->load.weight;
> +       load = cfs_rq->avg.load_avg;
>
>         shares = (tg->shares * load);
>         if (tg_weight)

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Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-23 20:40 +0200
  Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-23 20:50 +0200
    Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Jirka Hladky <jhladky@redhat.com> - 2016-06-24 09:50 +0200
      Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 10:10 +0200
        Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Jirka Hladky <jhladky@redhat.com> - 2016-06-24 10:30 +0200
      Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Jirka Hladky <jhladky@redhat.com> - 2016-06-24 14:10 +0200
        Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Jirka Hladky <jhladky@redhat.com> - 2016-06-24 14:40 +0200
        Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 14:40 +0200
      Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 14:10 +0200
        Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Vincent Guittot <vincent.guittot@linaro.org> - 2016-06-24 14:50 +0200
          Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 15:10 +0200
            Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Vincent Guittot <vincent.guittot@linaro.org> - 2016-06-24 15:30 +0200
              Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 15:40 +0200
              Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 15:50 +0200
          Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Jirka Hladky <jhladky@redhat.com> - 2016-06-24 15:10 +0200
          Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 15:50 +0200
            Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Peter Zijlstra <peterz@infradead.org> - 2016-06-24 18:00 +0200
              Re: Kernel 4.7rc3 - Performance drop 30-40% for SPECjbb2005 and  SPECjvm2008 benchmarks against 4.6 kernel Jirka Hladky <jhladky@redhat.com> - 2016-06-25 00:20 +0200

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