Message-ID: <1438452063.2249.98.camel@stgolabs.net>
Subject: Re: [PATCH v4 1/7] locking/pvqspinlock: Unconditional PV kick with
 _Q_SLOW_VAL
From: Davidlohr Bueso <dave@stgolabs.net>
To: Waiman Long <Waiman.Long@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
        x86@kernel.org, linux-kernel@vger.kernel.org,
        Scott J Norton <scott.norton@hp.com>,
        Douglas Hatch <doug.hatch@hp.com>
Date: Sat, 01 Aug 2015 11:01:03 -0700
In-Reply-To: <1438395724-25910-2-git-send-email-Waiman.Long@hp.com>
References: <1438395724-25910-1-git-send-email-Waiman.Long@hp.com>
	 <1438395724-25910-2-git-send-email-Waiman.Long@hp.com>
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On Fri, 2015-07-31 at 22:21 -0400, Waiman Long wrote:
> The smp_store_release() is not a full barrier. In order to avoid missed
> wakeup, we may need to add memory barrier around locked and cpu state
> variables adding to complexity. As the chance of spurious wakeup is very
> low, it is easier and safer to just do an unconditional kick at unlock
> time.
> 
> Signed-off-by: Waiman Long <Waiman.Long@hp.com>

Please keep tags from previous versions ;)

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