From: Peter Zijlstra <peterz@infradead.org>
To: Kirill Tkhai <ktkhai@parallels.com>
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 12:26:16 +0100 [thread overview]
Message-ID: <20150217112616.GU24151@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20150217111116.GL5029@twins.programming.kicks-ass.net>
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.
next prev parent reply other threads:[~2015-02-17 11:26 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 [this message]
2015-02-17 11:33 ` Kirill Tkhai
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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