From: Ingo Molnar <mingo@kernel.org>
To: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
NeilBrown <neilb@suse.de>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
lkml <linux-kernel@vger.kernel.org>,
"Dr. H. Nikolaus Schaller" <hns@goldelico.com>,
Marek Belisko <marek@goldelico.com>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH/RFC] wait_for_completion_timeout() considered harmful.
Date: Tue, 19 Nov 2013 08:05:57 +0100 [thread overview]
Message-ID: <20131119070557.GD32367@gmail.com> (raw)
In-Reply-To: <20131118174902.312d8fa6@lwn.net>
* Jonathan Corbet <corbet@lwn.net> wrote:
> On Tue, 19 Nov 2013 00:42:09 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
>
> > I briefly talked to Thomas about this earlier today and we need to
> > fix this at a lower level -- the quick 'n dirty solution is to add
> > 1 jiffy down in the timer-wheel when we enqueue these things.
>
> That can lead to situations like the one I encountered years ago
> where msleep(1) would snooze for 20ms. I didn't get much love for
> my idea of switching msleep() to hrtimers back then, but I still
> think it might be be better to provide the resolution that the
> interface appears to promise.
That looks like a sensible approach - mind resending that patch? We
can put it into the timer tree and see what happens.
Thanks,
Ingo
next prev parent reply other threads:[~2013-11-19 7:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-16 21:06 [PATCH/RFC] wait_for_completion_timeout() considered harmful NeilBrown
2013-11-18 23:27 ` Andrew Morton
2013-11-18 23:42 ` Peter Zijlstra
2013-11-19 0:49 ` Jonathan Corbet
2013-11-19 7:05 ` Ingo Molnar [this message]
2013-11-19 8:29 ` Peter Zijlstra
2013-11-18 23:44 ` NeilBrown
2013-11-19 8:25 ` Peter Zijlstra
2013-11-19 8:58 ` NeilBrown
2013-11-19 12:23 ` Peter Zijlstra
2013-11-19 14:39 ` Thomas Gleixner
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