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From: afzal.mohd.ma@gmail.com (Afzal Mohammed)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm: spin one more cycle in timer-based delays
Date: Sun, 20 Nov 2016 11:45:21 +0530	[thread overview]
Message-ID: <20161120061521.GA4307@afzalpc> (raw)
In-Reply-To: <20161119110301.GQ1041@n2100.armlinux.org.uk>

Hi Russell,

On Sat, Nov 19, 2016 at 11:03:01AM +0000, Russell King - ARM Linux wrote:

> > > 6c5e9059692567740a4ee51530dffe51a4b9584d
> > > https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?h=timers/core&id=6c5e9059692567740a4ee51530dffe51a4b9584d
> > 
> > But the above "timers: Fix usleep_range() in the context of
> > wake_up_process()" is to avoid wakeup causing premature return than
> > about being precise, no ?

> usleep*() is based on the scheduler, which has tighter requirements
> laid down in POSIX amongst other standards, such as "not timing out
> before this specified time"

Thanks for educating on the POSIX linkage.

When the above mentioned patch was flying, tglx initially mentioned
that there is no gurantee that usleep_range() will never return in less
time than the specified minimum, but later he committed the change to
tip-bot keeping the message saying otherwise. That was confusing, and
me being a wayfarer, didn't have the courage to ask.

Regards
afzal

  parent reply	other threads:[~2016-11-20  6:15 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-15 13:36 [PATCH] arm: spin one more cycle in timer-based delays Mason
2016-11-18 12:06 ` Will Deacon
2016-11-18 12:24   ` Mason
2016-11-18 12:54   ` Russell King - ARM Linux
2016-11-18 14:18     ` Mason
2016-11-18 14:42       ` Peter Zijlstra
2016-11-18 17:51       ` Mason
2016-11-19  7:17       ` Afzal Mohammed
2016-11-19 11:03         ` Russell King - ARM Linux
2016-11-19 18:29           ` Mason
2016-11-20 19:18             ` Doug Anderson
2016-11-20 19:44               ` Russell King - ARM Linux
2016-11-20 20:00                 ` Mason
2016-11-20  6:15           ` Afzal Mohammed [this message]
2016-11-20 19:15           ` Doug Anderson
2016-11-18 17:13     ` Doug Anderson
2016-11-18 17:32       ` Russell King - ARM Linux

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