Re: tickless and HZ=1000 throughput advantage?

[Arjan van de Ven]

On Sun, 20 Sep 2009 09:34:30 +0200
Tim Blechmann <tim@xxxxxxxxxx> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/