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Date: Thu, 04 Mar 2010 09:33:29 +0800
From: Li Zefan <lizf@cn.fujitsu.com>
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CC: LKML <linux-kernel@vger.kernel.org>, Steven Rostedt <rostedt@goodmis.org>,
       Frederic Weisbecker <fweisbec@gmail.com>, Ingo Molnar <mingo@elte.hu>
Subject: Re: 2.6.33: ftrace triggers soft lockup
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Américo Wang wrote:
> Hi, Steven, Frederic, Ingo,
> 
> I am not sure if this is ftrace's fault, but it is ftrace who triggers
> the soft lockup. On my machine, it is pretty easy, just run:
> 
> echo function_graph > current_tracer
> 
> I found this when 2.6.33-rc7, but forgot to report here. I just tried today's
> Linus tree, it still has this problem.
> 

I can also trigger soft lockup while running a stress test for ftrace.

I'll post detailed information after more testing.