Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers and writers of load_avg

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers and writers of load_avg
Date	2015-11-30 23:20 +0100
Message-ID	<qAEXE-11R-23@gated-at.bofh.it> (permalink)
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On Mon, Nov 30, 2015 at 02:13:32PM -0500, Waiman Long wrote:
> >This begs the question tough; why are you running a global load in a
> >cgroup; and do we really need to update this for the root cgroup? It
> >seems to me we don't need calc_tg_weight() for the root cgroup, it
> >doesn't need to normalize its weight numbers.
> >
> >That is; isn't this simply a problem we should avoid?
> 
> I didn't use any cgroup in my test setup. Autogroup was enabled, though.
> Booting up a 4.4-rc2 kernel caused sched_create_group() to be called 56
> times.

Yeah, can you kill autogroup and see if that helps? If not, we probably
should add some code to avoid calculating things for the root group.
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Thread

[RFC PATCH 3/3] sched/fair: Use different cachelines for readers and writers of load_avg Waiman Long <Waiman.Long@hpe.com> - 2015-11-25 20:20 +0100
  Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Peter Zijlstra <peterz@infradead.org> - 2015-11-30 11:30 +0100
    Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Waiman Long <waiman.long@hpe.com> - 2015-11-30 20:20 +0100
      Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Peter Zijlstra <peterz@infradead.org> - 2015-11-30 23:20 +0100
        Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Waiman Long <waiman.long@hpe.com> - 2015-12-01 05:00 +0100
          Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Peter Zijlstra <peterz@infradead.org> - 2015-12-01 09:50 +0100
            Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for  readers and writers of load_avg Mike Galbraith <umgwanakikbuti@gmail.com> - 2015-12-01 11:50 +0100
            Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Waiman Long <waiman.long@hpe.com> - 2015-12-02 19:50 +0100
      Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Peter Zijlstra <peterz@infradead.org> - 2015-11-30 23:30 +0100
        Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Waiman Long <waiman.long@hpe.com> - 2015-12-01 05:10 +0100
          Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Peter Zijlstra <peterz@infradead.org> - 2015-12-01 09:50 +0100
            Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Waiman Long <waiman.long@hpe.com> - 2015-12-02 19:50 +0100
      Re: [RFC PATCH 3/3] sched/fair: Use different cachelines for readers  and writers of load_avg Peter Zijlstra <peterz@infradead.org> - 2015-11-30 23:40 +0100

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