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Date:   Thu, 19 May 2022 09:47:52 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Uros Bizjak <ubizjak@gmail.com>
Cc:     linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: Re: [PATCH] sched/clock: Use try_cmpxchg64 in
 sched_clock_{local,remote}
Message-ID: <20220519074752.GC2578@worktop.programming.kicks-ass.net>
References: <20220518184953.3446778-1-ubizjak@gmail.com>
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On Wed, May 18, 2022 at 08:49:53PM +0200, Uros Bizjak wrote:
> Use try_cmpxchg64 instead of cmpxchg64 (*ptr, old, new) != old in
> sched_clock_{local,remote}. x86 cmpxchg returns success in ZF flag,
> so this change saves a compare after cmpxchg (and related move
> instruction in front of cmpxchg).
> 
> Signed-off-by: Uros Bizjak <ubizjak@gmail.com>

Thanks!