From: Arjan van de Ven <arjan@infradead.org>
To: Tim Blechmann <tim@klingt.org>
Cc: linux-kernel@vger.kernel.org,
Daniel J Blueman <daniel.blueman@gmail.com>
Subject: Re: tickless and HZ=1000 throughput advantage?
Date: Sun, 20 Sep 2009 09:40:22 +0200 [thread overview]
Message-ID: <20090920094022.0609f56c@infradead.org> (raw)
In-Reply-To: <4AB5DB06.1090100@klingt.org>
On Sun, 20 Sep 2009 09:34:30 +0200
Tim Blechmann <tim@klingt.org> wrote:
> On 09/20/2009 01:12 AM, Ben Nizette wrote:
> > On Sat, 2009-09-19 at 18:50 +0100, Daniel J Blueman wrote:
> >
> >> Agreed. Do you think there is still a small case for moving to
> >> HZ=1000 (given it's effectively free) in situations like:
> >
> > Sure HZ=1000 gives you more accurate sleeps, that's kind of the
> > point, but since when has it been "effectively free"?
> > http://lwn.net/Articles/331607/
>
> i'd be curious, what effect does it have on userspace applications?
> like, does it effect the wakeup latency of userspace (pthread)
> mutexes/conditions or posix semaphores?
the impact to userspace should be zero nowadays since select/poll/etc
moved to hrtimers, which are HZ-independent.
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
prev parent reply other threads:[~2009-09-20 7:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-19 14:47 tickless and HZ=1000 throughput advantage? Daniel J Blueman
2009-09-19 14:55 ` Arjan van de Ven
2009-09-19 17:50 ` Daniel J Blueman
2009-09-19 23:12 ` Ben Nizette
2009-09-20 7:34 ` Tim Blechmann
2009-09-20 7:40 ` Arjan van de Ven [this message]
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