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Date: Tue, 21 Apr 2009 20:33:23 +0200
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       Andrew Morton <akpm@linux-foundation.org>,
       Zhaolei <zhaolei@cn.fujitsu.com>, Steven Rostedt <rostedt@goodmis.org>,
       Tom Zanussi <tzanussi@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/1] ftrace, workqueuetrace: Make
	workqueuetracepoints use TRACE_EVENT macro
Message-ID: <20090421183322.GC6001@nowhere>
References: <20090420103612.4B4E.A69D9226@jp.fujitsu.com> <47EF9F5C609F496FBBD423EA81A00920@zhaoleiwin> <20090420104734.4B51.A69D9226@jp.fujitsu.com> <20090420084631.GA32625@elte.hu> <20090420222514.GA15680@redhat.com> <20090420234835.GC5997@nowhere> <20090421152843.GA5402@redhat.com> <20090421155032.GB5402@redhat.com>
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On Tue, Apr 21, 2009 at 05:50:32PM +0200, Oleg Nesterov wrote:
> On 04/21, Oleg Nesterov wrote:
> >
> > On 04/21, Frederic Weisbecker wrote:
> > >
> > > For example,
> > >
> > > - the user opens the stat file
> > > - then the entries are loaded and sorted into memory
> > > - one of the workqueues is destroyed
> 
> Hmm. And what protects cws when, say, workqueue_stat_show() is called?
> Can't we race with probe_workqueue_destruction()->kfree() ?
> 
> Oleg.
>


Indeed. I plan to implement a waitqueue on the stat tracing framework
to fix it (per tracer of course).

Thanks. 

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