Messages in this thread | | | Date | Fri, 20 Nov 2009 01:57:46 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 2/2] lockdep: Don't only check recursive read locks once in a sequence |
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On Thu, Nov 19, 2009 at 06:13:48PM +0100, Peter Zijlstra wrote: > On Thu, 2009-11-19 at 16:55 +0100, Frederic Weisbecker wrote: > > And btw I > > don't understand why rwsem read locks are not considered as > > recursive in lockdep. > > Because they're not. > > rwsems are FIFO fair, so a double read can deadlock when there's a > pending writer inbetween. >
Aah ok. That's the subtle thing I was missing :)
Thanks.
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