Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched domain build-up

From	Yuyang Du <yuyang.du@intel.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched domain build-up
Date	2016-06-02 05:40 +0200
Message-ID	<rFrEd-Dz-3@gated-at.bofh.it> (permalink)
References	(4 earlier) <rF6zM-4aY-3@gated-at.bofh.it> <rF9ej-5BV-39@gated-at.bofh.it> <rF9R1-641-61@gated-at.bofh.it> <rFak1-6tA-15@gated-at.bofh.it> <rFaDo-6Ci-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Jun 01, 2016 at 11:24:45AM +0200, Vincent Guittot wrote:
> >
> > So with the patch, we will have a little bit semantic change, SD_BALANCE_WAKE
> > implies SD_WAKE_AFFINE if allowed, and will favor "fast path" if possible. I don't
> > think we should do anything otherwise.
> 
> Why should we not do anything else ?
> 
> The current default configuration is to only use the wake_affine path.
> With your changes, the default configuration will try to use wake
> affine and will fall back to long load balance sequence if wake affine
> doesn't find a sched_domain
> 
> That's a major changes in the behavior

Well, I won't argue that this hasn't changed, but I'd argue that this change
isn't a bad change: (a) it restores the flags to their meanings and makes them
more "elegant", (b) we definitely need further work to improve
select_task_rq_fair(), there has already been a comment marked XXX, right? :)

Thread

[RFC PATCH 0/2] Remove and replace SD_WAKE_AFFINE with SD_BALANCE_WAKE Yuyang Du <yuyang.du@intel.com> - 2016-05-31 11:10 +0200
  [RFC PATCH 2/2] sched: Remove SD_WAKE_AFFINE flag and replace it with SD_BALANCE_WAKE Yuyang Du <yuyang.du@intel.com> - 2016-05-31 11:10 +0200
    Re: [RFC PATCH 2/2] sched: Remove SD_WAKE_AFFINE flag and replace it  with SD_BALANCE_WAKE Peter Zijlstra <peterz@infradead.org> - 2016-05-31 11:30 +0200
      Re: [RFC PATCH 2/2] sched: Remove SD_WAKE_AFFINE flag and replace it  with SD_BALANCE_WAKE Yuyang Du <yuyang.du@intel.com> - 2016-05-31 11:40 +0200
  [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-05-31 11:10 +0200
    Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-05-31 11:30 +0200
      Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Peter Zijlstra <peterz@infradead.org> - 2016-05-31 12:50 +0200
        Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-01 04:00 +0200
      Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-06-01 07:10 +0200
        Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-01 10:00 +0200
          Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Vincent Guittot <vincent.guittot@linaro.org> - 2016-06-01 10:40 +0200
            Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-01 11:10 +0200
              Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Vincent Guittot <vincent.guittot@linaro.org> - 2016-06-01 11:30 +0200
                Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-02 05:40 +0200
                Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Vincent Guittot <vincent.guittot@linaro.org> - 2016-06-02 09:00 +0200
                Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-02 09:20 +0200
          Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-06-01 11:40 +0200
            Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-02 06:10 +0200
              Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-06-02 08:00 +0200
                Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Yuyang Du <yuyang.du@intel.com> - 2016-06-02 08:40 +0200
                Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-06-02 08:50 +0200
    Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched  domain build-up Peter Zijlstra <peterz@infradead.org> - 2016-05-31 11:30 +0200

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