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Date: Tue, 30 Sep 2008 09:09:23 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Steven Rostedt <rostedt@goodmis.org>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Rusty Russell <rusty@rustcorp.com.au>,
       "Frank Ch. Eigler" <fche@redhat.com>,
       Lai Jiangshan <laijs@cn.fujitsu.com>
Subject: Re: [PATCH] Markers : fix reentrancy
Message-ID: <20080930070923.GB30927@elte.hu>
References: <20080930054151.GA16961@Krystal>
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* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:

> Lai Jiangshan <laijs@cn.fujitsu.com> wrote :
> > marker_synchronize_unregister must be called _also_ between unregistration
> > and destruction the data that unregistration-ed probes need to make sure
> > there is no caller executing a probe when it's data is destroyed.
> > 
> 
> Ah, you're right. I looked again through your patch description and I
> think using a :
> 
> 
> if (entry->rcu_pending)
>                 rcu_barrier_sched();
> 
> After each time the markers_mutex is taken would keep the fast batch 
> registration/unregistration and fix the reentrancy problem. The 
> following patch should address the problem.

could you please send a delta patch against tip/master? Lai's patch is 
already applied and is tested. Thanks,

	Ingo