From: Yong Zhang <yong.zhang0@gmail.com>
To: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
netdev@vger.kernel.org, Ben Dooks <ben-linux@fluff.org>
Subject: Re: [PATCH 1/2] workqueue: Catch more locking problems with flush_work()
Date: Fri, 20 Apr 2012 13:26:33 +0800 [thread overview]
Message-ID: <20120420052633.GA16219@zhy> (raw)
In-Reply-To: <4F905B30.4080501@codeaurora.org>
On Thu, Apr 19, 2012 at 11:36:32AM -0700, Stephen Boyd wrote:
> Does looking at the second patch help? Basically schedule_work() can run
> the callback right between the time the mutex is acquired and
> flush_work() is called:
>
> CPU0 CPU1
>
> <irq>
> schedule_work() mutex_lock(&mutex)
> <irq return>
> my_work() flush_work()
> mutex_lock(&mutex)
> <deadlock>
Get you point. It is a problem. But your patch could introduece false
positive since when flush_work() is called that very work may finish
running already.
So I think we need the lock_map_acquire()/lock_map_release() only when
the work is under processing, no?
Thanks,
Yong
next prev parent reply other threads:[~2012-04-20 5:26 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-19 3:25 [PATCH 1/2] workqueue: Catch more locking problems with flush_work() Stephen Boyd
2012-04-19 3:25 ` [PATCH 2/2] ks8851: Fix mutex deadlock in ks8851_net_stop() Stephen Boyd
2012-04-21 19:34 ` David Miller
2012-04-19 8:10 ` [PATCH 1/2] workqueue: Catch more locking problems with flush_work() Yong Zhang
2012-04-19 18:36 ` Stephen Boyd
2012-04-20 5:26 ` Yong Zhang [this message]
2012-04-20 6:01 ` Yong Zhang
2012-04-20 6:26 ` Stephen Boyd
2012-04-20 7:18 ` Yong Zhang
2012-04-20 8:18 ` Stephen Boyd
2012-04-20 8:32 ` Yong Zhang
2012-04-21 0:32 ` Yong Zhang
2012-04-19 15:28 ` Tejun Heo
2012-04-19 18:10 ` Stephen Boyd
2012-04-20 17:35 ` Tejun Heo
2012-04-20 23:15 ` Stephen Boyd
2012-04-21 0:28 ` [PATCHv2] " Stephen Boyd
2012-04-21 0:34 ` Yong Zhang
2012-04-23 18:07 ` Tejun Heo
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