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From: Yuyang Du <yuyang.du@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@kernel.org, linux-kernel@vger.kernel.org,
	umgwanakikbuti@gmail.com, bsegall@google.com, pjt@google.com,
	morten.rasmussen@arm.com, vincent.guittot@linaro.org,
	dietmar.eggemann@arm.com
Subject: Re: [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched domain build-up
Date: Wed, 1 Jun 2016 02:00:30 +0800	[thread overview]
Message-ID: <20160531180030.GS18670@intel.com> (raw)
In-Reply-To: <20160531104121.GJ3190@twins.programming.kicks-ass.net>

On Tue, May 31, 2016 at 12:41:21PM +0200, Peter Zijlstra wrote:
> On Tue, May 31, 2016 at 09:31:32AM +0800, Yuyang Du wrote:
> > On Tue, May 31, 2016 at 11:21:46AM +0200, Peter Zijlstra wrote:
> > > On Tue, May 31, 2016 at 09:11:37AM +0800, Yuyang Du wrote:
> > > > The SD_BALANCE_WAKE is irrelevant in the contexts of these two removals,
> > > > and in addition SD_BALANCE_WAKE is not and should not be set in any
> > > > sched_domain flags so far.
> > > 
> > > This Changelog doesn't make any sense...
> > 
> > How? SD_BALANCE_WAKE is not in any sched_domain flags (sd->flags), even if
> > it is, it is not used anywhere, no?
> 
> It is and it is. See select_task_fair_rq():
> 
> 	if (tmp->flags & sd_flags)
> 
> Now, as long as WAKE_AFFINE is also set, its hard to actually get into
> the find_idlest_cpu() balancing, but if you clear all that you will
> still get there.
 
Well, that is very true, and the next patch (2/2) just makes all this
what this is supposed to be: the SD_BALANCE_WAKE is a meaningful sched_domain
flag.

This particular patch is a pure cleanup, may I amend the changelog to:

According to the comment: "turn off/on idle balance on this domain",
the SD_BALANCE_WAKE has nothing to do with idle balance, so clean them up.

  reply	other threads:[~2016-06-01  1:58 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-31  1:11 [RFC PATCH 0/2] Remove and replace SD_WAKE_AFFINE with SD_BALANCE_WAKE Yuyang Du
2016-05-31  1:11 ` [RFC PATCH 1/2] sched: Clean up SD_BALANCE_WAKE flags in sched domain build-up Yuyang Du
2016-05-31  9:21   ` Peter Zijlstra
2016-05-31  1:31     ` Yuyang Du
2016-05-31 10:41       ` Peter Zijlstra
2016-05-31 18:00         ` Yuyang Du [this message]
2016-06-01  5:07       ` Mike Galbraith
2016-06-01  0:01         ` Yuyang Du
2016-06-01  8:32           ` Vincent Guittot
2016-06-01  1:03             ` Yuyang Du
2016-06-01  9:24               ` Vincent Guittot
2016-06-01 19:35                 ` Yuyang Du
2016-06-02  6:56                   ` Vincent Guittot
2016-06-01 23:19                     ` Yuyang Du
2016-06-01  9:36           ` Mike Galbraith
2016-06-01 20:03             ` Yuyang Du
2016-06-02  5:50               ` Mike Galbraith
2016-06-01 22:41                 ` Yuyang Du
2016-06-02  6:44                   ` Mike Galbraith
2016-05-31  1:11 ` [RFC PATCH 2/2] sched: Remove SD_WAKE_AFFINE flag and replace it with SD_BALANCE_WAKE Yuyang Du
2016-05-31  9:23   ` Peter Zijlstra
2016-05-31  1:34     ` Yuyang Du

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