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Date: Wed, 9 Jun 2010 21:06:10 +0100
From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Ortwin =?iso-8859-1?Q?Gl=FCck?= <odi@odi.ch>
Cc: linux-kernel@vger.kernel.org
Subject: Re: freeze when strace X
Message-ID: <20100609200610.GA27536@srcf.ucam.org>
References: <4C0FDF9F.9070000@odi.ch> <20100609195228.GA27088@srcf.ucam.org> <4C0FF34D.6090800@odi.ch>
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On Wed, Jun 09, 2010 at 10:02:21PM +0200, Ortwin Gl?ck wrote:
> On 09.06.2010 21:52, Matthew Garrett wrote:
> > Just to make sure, you're not trying to strace X from within X, are you?
> 
> Oh... now that you mention it... Is that a silly thing to do?
> strace X from a different terminal works fine :-)
> 
> But freezing the system because of that? I mean an error message, log, anything
> would be "nice".

strace needs to output text via X, which generates output which needs to 
be output via X... and you'll tend to deadlock. If X is holding any 
interesting kernel locks at that point then it wouldn't surprise me if 
the machine ends up dead.

-- 
Matthew Garrett | mjg59@srcf.ucam.org
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