Messages in this thread | ![/](/images/icornerl.gif) | | Date | Sun, 20 Sep 2009 09:40:22 +0200 | From | Arjan van de Ven <> | Subject | Re: tickless and HZ=1000 throughput advantage? |
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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
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