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From: Rusty Russell <rusty@rustcorp.com.au>
To: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux-kernel@vger.kernel.org, Matthew Wilcox <matthew@wil.cx>,
	Randy Dunlap <rdunlap@xenotime.net>,
	linux-doc@vger.kernel.org
Subject: Re: [PATCH] Documentation: kernel-locking: mutex_trylock cannot be used in interrupt context
Date: Thu, 19 Aug 2010 10:22:42 +0930	[thread overview]
Message-ID: <201008191022.43524.rusty@rustcorp.com.au> (raw)
In-Reply-To: <tkrat.12a11fb05527c6ed@s5r6.in-berlin.de>

On Thu, 19 Aug 2010 07:38:15 am Stefan Richter wrote:
> Chapter 6 is right about mutex_trylock, but chapter 10 wasn't.
> This error was introduced during semaphore-to-mutex conversion of the
> Unreliable guide. :-)
> 
> If user context which performs mutex_lock() or mutex_trylock() is
> preempted by interrupt context which performs mutex_trylock() on the
> same mutex instance, a deadlock occurs.  This is because these functions
> do not disable local IRQs when they operate on mutex->wait_lock.

Acked-by: Rusty Russell <rusty@rustcorp.com.au>

I'm assuming Andrew Morton or Randy Dunlap will pick this up...

Thanks!
Rusty.

      reply	other threads:[~2010-08-19  0:52 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-18 22:08 [PATCH] Documentation: kernel-locking: mutex_trylock cannot be used in interrupt context Stefan Richter
2010-08-19  0:52 ` Rusty Russell [this message]

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