linux-kernel - Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched

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Date:	Mon, 23 May 2016 12:26:33 +0200
From:	Mike Galbraith <umgwanakikbuti@...il.com>
To:	Wanpeng Li <kernellwp@...il.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Pavan Kondeti <pkondeti@...eaurora.org>,
	Ben Segall <bsegall@...gle.com>,
	Matt Fleming <matt@...eblueprint.co.uk>,
	Morten Rasmussen <morten.rasmussen@....com>,
	Paul Turner <pjt@...gle.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Byungchul Park <byungchul.park@....com>,
	Andrew Hunter <ahh@...gle.com>
Subject: Re: [patch] sched/fair: Move se->vruntime normalization state into
 struct sched_entity

On Mon, 2016-05-23 at 18:13 +0800, Wanpeng Li wrote:
> 2016-05-23 17:40 GMT+08:00 Mike Galbraith <umgwanakikbuti@...il.com>:
> > On Mon, 2016-05-23 at 11:19 +0200, Peter Zijlstra wrote:
> > > On Sun, May 22, 2016 at 09:00:01AM +0200, Mike Galbraith wrote:
> > > > On Sat, 2016-05-21 at 21:00 +0200, Mike Galbraith wrote:
> > > > > On Sat, 2016-05-21 at 16:04 +0200, Mike Galbraith wrote:
> > > > > 
> > > > > > Wakees that were not migrated/normalized eat an unwanted
> > > > > > min_vruntime,
> > > > > > and likely take a size XXL latency hit.  Big box running
> > > > > > master bled
> > > > > > profusely under heavy load until I turned TTWU_QUEUE off.
> > > > 
> > > > May as well make it official and against master.today.  Fly or
> > > > die
> > > > little patchlet.
> > > > 
> > > > sched/fair: Move se->vruntime normalization state into struct
> > > > sched_entity
> > > 
> > > Does this work?
> > 
> > Yup, bugs--.  Kinda funny, I considered ~this way first, but
> > thought
> > you'd not that approach.. dang, got it back-assward ;-)
> > 
> 
> Nicer this one.

Well, the wakeup is a remote wakeup whether the flag is set or not, so
in that regard it's not _squeaky_ clean, but is dinky, works (yay)..
and doesn't invent helpers with funny names vs what they actually do.

	-Mike