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Date:   Thu, 29 Nov 2018 23:05:44 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Waiman Long <longman@redhat.com>
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        Davidlohr Bueso <dave@stgolabs.net>
Subject: Re: [RFC] locking/rwsem: Avoid issuing wakeup before setting the
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On Thu, Nov 29, 2018 at 01:34:05PM -0500, Waiman Long wrote:

> That will certainly work for x86. However, I am not sure if that will be
> optimal for arm and powerpc.

	smp_mb__before_atomic()
	cmpxchg_relaxed()

works. Also see pv_kick_node()'s commit:

  34d54f3d6917 ("locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures")

you might know the author of that :-)