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From: Kirill Tkhai <ktkhai@parallels.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@redhat.com>,
	"Josh Poimboeuf" <jpoimboe@redhat.com>
Subject: Re: [PATCH 1/2] sched: Move __task_rq_{, un}lock() to kernel/sched/sched.h
Date: Tue, 17 Feb 2015 14:33:58 +0300	[thread overview]
Message-ID: <1424172838.5749.27.camel@tkhai> (raw)
In-Reply-To: <20150217112616.GU24151@twins.programming.kicks-ass.net>

В Вт, 17/02/2015 в 12:26 +0100, Peter Zijlstra пишет:
> On Tue, Feb 17, 2015 at 12:11:16PM +0100, Peter Zijlstra wrote:
> > On Tue, Feb 17, 2015 at 01:46:51PM +0300, Kirill Tkhai wrote:
> > > 
> > > Place it in sched.h, because dl_task_timer() needs it.
> > > Also remove lockdep check, which is not fit to this
> > > function.
> > 
> > No, that lockdep check is valid for all current sites.
> 
> Also, note that you just proved the reason we didn't have pi_lock there
> wrong the other day.
> 
> As per 0f397f2c90ce ("sched/dl: Fix race in dl_task_timer()"):
> 
>        "The only reason we don't strictly need ->pi_lock now is because
>         we're guaranteed to have p->state == TASK_RUNNING here and are
>         thus free of ttwu races".
> 
> And therefore we should use the full task_rq_lock() here.
> 

So, we move task_rq_lock() to sched.h, and dl_task_timer() uses it?



  reply	other threads:[~2015-02-17 11:34 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-17 10:46 [PATCH 1/2] sched: Move __task_rq_{, un}lock() to kernel/sched/sched.h Kirill Tkhai
2015-02-17 11:11 ` Peter Zijlstra
2015-02-17 11:20   ` Kirill Tkhai
2015-02-17 11:26   ` Peter Zijlstra
2015-02-17 11:33     ` Kirill Tkhai [this message]
2015-02-17 12:31       ` [PATCH] sched: Make dl_task_time() use task_rq_lock() Peter Zijlstra
2015-02-17 13:32         ` Peter Zijlstra
2015-02-18 17:06         ` [tip:sched/core] " tip-bot for Peter Zijlstra

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