From: Avi Kivity <avi@redhat.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Tejun Heo <tj@kernel.org>, lkml <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 2.6.32-rc6] sched, kvm: fix race condition involving sched_in_preempt_notifers
Date: Sat, 14 Nov 2009 15:06:53 +0200 [thread overview]
Message-ID: <4AFEAB6D.60600@redhat.com> (raw)
In-Reply-To: <20091113095516.GD1364@elte.hu>
On 11/13/2009 11:55 AM, Ingo Molnar wrote:
> * Tejun Heo<tj@kernel.org> wrote:
>
>
>> In finish_task_switch(), fire_sched_in_preempt_notifiers() is called
>> after finish_lock_switch(). However, depending on architecture,
>> preemption can be enabled after finish_lock_switch() which breaks the
>> semantics of preempt notifiers. Move it before finish_arch_switch().
>> This also makes in notifiers symmetric to out notifiers in terms of
>> locking - now both are called under rq lock.
>>
>>
> I'd like to have Avi's Ack for it,
Acked-by: Avi Kivity <avi@redhat.com>
> but we want to do sched.c changes via
> the scheduler tree.
>
Definitely.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
next prev parent reply other threads:[~2009-11-14 13:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-13 9:33 [PATCH 2.6.32-rc6] sched, kvm: fix race condition involving sched_in_preempt_notifers Tejun Heo
2009-11-13 9:55 ` Ingo Molnar
2009-11-14 13:06 ` Avi Kivity [this message]
2009-11-30 9:09 ` Tejun Heo
2009-11-30 9:45 ` Avi Kivity
2009-11-30 10:00 ` Ingo Molnar
2009-11-30 10:11 ` Avi Kivity
2009-11-30 11:41 ` [PATCH UPDATED " Tejun Heo
2009-11-15 10:29 ` [tip:sched/urgent] sched, kvm: Fix " tip-bot for Tejun Heo
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