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Subject: Re: [patch] doc: add a chapter about trylock functions [Bug 9011]
From: Peter Zijlstra <peterz@infradead.org>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matti Linnanvuori <mattilinn@gmail.com>,
       Randy Dunlap <randy.dunlap@oracle.com>,
       Andrew Morton <akpm@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>,
       linux-kernel@vger.kernel.org
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	 <200805151030.18959.rusty@rustcorp.com.au>
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Date: Fri, 16 May 2008 14:21:25 +0200
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On Thu, 2008-05-15 at 10:30 +1000, Rusty Russell wrote:
> On Wednesday 14 May 2008 01:31:47 Matti Linnanvuori wrote:
> > +    <function>mutex_trylock()</function> does not suspend your task
> > +    but returns non-zero if it could lock the mutex on the first try
> > +    or 0 if not. This function cannot be safely used in hardware or
> > +    software interrupt contexts despite not sleeping.
> 
> I know this is what the documentation says, but I can't see why.  Ingo?

because who would then own the lock?