Subject: Re: [PATCH] sched: remove resetting exec_start in
 put_prev_task_rt()
From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>, Hillf Danton <dhillf@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>, Mike Galbraith <efault@gmx.de>,
        Ingo Molnar <mingo@elte.hu>
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Date: Fri, 10 Jun 2011 12:19:06 +0200
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On Thu, 2011-06-09 at 22:41 -0400, Steven Rostedt wrote:
> On Fri, 2011-06-10 at 10:38 +0800, Yong Zhang wrote:
> > On Thu, Jun 9, 2011 at 8:34 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> > > I disagree. Yes the exec_start is reset there, but I like the fact that
> > > it's 0 when not running.
> > 
> > Actually this depends on how we look at the code:
> > if we set exec_start to 0 explicitly, as you said the code is more direct and
> > readable.
> > if we don't set exec_start to 0, we can save one instruction though
> > it's minor.
> > 
> > I have no strong opinion on either of them :)
> 
> I don't have any real strong opinion on this either, so I'll just let
> Peter decide :)

Yay! So IFF its correct (I didn't check) then sure it saves a whole
store :-), I don't think sched_fair clears exec_start on de-schedule
either.
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