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}
Date: Thu, 19 May 2022 09:47:52 +0200 [thread overview]
Message-ID: <20220519074752.GC2578@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20220518184953.3446778-1-ubizjak@gmail.com>
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!
next prev parent reply other threads:[~2022-05-19 7:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 18:49 [PATCH] sched/clock: Use try_cmpxchg64 in sched_clock_{local,remote} Uros Bizjak
2022-05-19 7:47 ` Peter Zijlstra [this message]
2022-05-19 21:49 ` [tip: locking/core] " tip-bot2 for Uros Bizjak
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