Re: Abysmal scheduler performance in Linus' tree?

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: Abysmal scheduler performance in Linus' tree?
Date	2017-09-06 18:20 +0200
Message-ID	<umLdw-4da-23@gated-at.bofh.it> (permalink)
References	<umAUN-57m-1@gated-at.bofh.it> <umDSG-7ph-7@gated-at.bofh.it> <umElI-7Em-27@gated-at.bofh.it> <umEvn-7XC-1@gated-at.bofh.it>
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On Wed, Sep 06, 2017 at 11:03:33AM +0200, Peter Zijlstra wrote:
> On Wed, Sep 06, 2017 at 01:59:14AM -0700, Andy Lutomirski wrote:
> > > Any specifics on your setup?
> > 
> > On further fiddling, I only see this after a suspend and resume cycle.
> 
> Ah, ok. That's not something I otherwise test. Lets see if I can force
> this brick of mine through a suspend-resume cycle :-)

I'd be suspicious of these here commits:

  77d1dfda0e79 ("sched/topology, cpuset: Avoid spurious/wrong domain rebuilds")
  09e0dd8e0f2e ("sched/topology: Avoid pointless rebuild")
  bbdacdfed2f5 ("sched/debug: Optimize sched_domain sysctl generation")

I tested them with regular hotplug, but suspend resume always is a tad
funny.

Thread

Abysmal scheduler performance in Linus' tree? Andy Lutomirski <luto@kernel.org> - 2017-09-06 07:20 +0200
  Re: Abysmal scheduler performance in Linus' tree? Peter Zijlstra <peterz@infradead.org> - 2017-09-06 10:30 +0200
    Re: Abysmal scheduler performance in Linus' tree? Andy Lutomirski <luto@amacapital.net> - 2017-09-06 11:00 +0200
      Re: Abysmal scheduler performance in Linus' tree? Peter Zijlstra <peterz@infradead.org> - 2017-09-06 11:10 +0200
        Re: Abysmal scheduler performance in Linus' tree? Peter Zijlstra <peterz@infradead.org> - 2017-09-06 18:20 +0200
          Re: Abysmal scheduler performance in Linus' tree? Mike Galbraith <efault@gmx.de> - 2017-09-07 08:20 +0200
            Re: Abysmal scheduler performance in Linus' tree? Ingo Molnar <mingo@kernel.org> - 2017-09-07 09:40 +0200
            [PATCH] sched/cpuset/pm: Fix cpuset vs suspend-resume Peter Zijlstra <peterz@infradead.org> - 2017-09-07 11:20 +0200
              Re: [PATCH] sched/cpuset/pm: Fix cpuset vs suspend-resume Peter Zijlstra <peterz@infradead.org> - 2017-09-07 11:30 +0200
                Re: [PATCH] sched/cpuset/pm: Fix cpuset vs suspend-resume "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2017-09-07 13:10 +0200
                Re: [PATCH] sched/cpuset/pm: Fix cpuset vs suspend-resume Tejun Heo <tj@kernel.org> - 2017-09-07 22:40 +0200
              [tip:sched/urgent] sched/cpuset/pm: Fix cpuset vs. suspend-resume  bugs tip-bot for Peter Zijlstra <tipbot@zytor.com> - 2017-09-07 12:40 +0200
  Re: Abysmal scheduler performance in Linus' tree? Chris Wilson <chris@chris-wilson.co.uk> - 2017-09-06 11:20 +0200
    Re: Abysmal scheduler performance in Linus' tree? Peter Zijlstra <peterz@infradead.org> - 2017-09-06 11:30 +0200
      Re: Abysmal scheduler performance in Linus' tree? Peter Zijlstra <peterz@infradead.org> - 2017-09-06 12:50 +0200
        Re: Abysmal scheduler performance in Linus' tree? Peter Zijlstra <peterz@infradead.org> - 2017-09-06 13:00 +0200
          [tip:sched/urgent] sched/fair: Fix wake_affine_llc() balancing  rules tip-bot for Peter Zijlstra <tipbot@zytor.com> - 2017-09-07 10:30 +0200

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