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Date: Sun, 22 Jul 2007 11:37:02 +1000
From: Paul Mackerras <paulus@samba.org>
To: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/2] OProfile - Enable SPU switch notification to detect
	currently active SPU tasks - update
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Andrew Morton writes:

> I still wonder about that barrier.  At the least it should be smp_mb(). 
> But aren't our set_bit() semantics _alone_ sufficient to make this barrier
> unneeded?

No, but our wake_up semantics certainly ought to be, if they aren't
already.  It's the wake_up which implies synchronization with other
tasks, not the set_bit.

Paul.