From: Peter Zijlstra <peterz@infradead.org>
To: cj.chengjian@huawei.com, tglx@linutronix.de, hpa@zytor.com,
linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
mingo@kernel.org
Cc: linux-tip-commits@vger.kernel.org
Subject: Re: [tip:sched/core] sched/idle: Micro-optimize the idle loop
Date: Thu, 26 Oct 2017 15:41:36 +0200 [thread overview]
Message-ID: <20171026134136.GR3165@worktop.lehotels.local> (raw)
In-Reply-To: <tip-54b933c6c954a8b7b0c2b40a1c4d3f7279d11e22@git.kernel.org>
On Thu, Oct 26, 2017 at 02:31:34AM -0700, tip-bot for Cheng Jian wrote:
> After patch (execution in loop):
> 872: 0f ae e8 lfence
> ARM64:
> After patch (execution in loop):
> c84: d5033d9f dsb ld
> @@ -225,7 +226,7 @@ static void do_idle(void)
> check_pgt_cache();
> rmb();
I never could find a reason for that rmb() to exist, it also lacks a
clarifying comment.
We should perhaps attempt removing that...
prev parent reply other threads:[~2017-10-26 13:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-25 11:28 [PATCH] sched/idle: fetch smp_processor_id out of the idle loop Cheng Jian
2017-10-26 9:31 ` [tip:sched/core] sched/idle: Micro-optimize " tip-bot for Cheng Jian
2017-10-26 13:41 ` Peter Zijlstra [this message]
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