Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt.

Lee Revell
2005-05-18T00:11:05Z

On Tue, 2005-05-17 at 20:03 -0400, Valdis.Kletnieks@vt.edu wrote:
> On Tue, 17 May 2005 19:25:41 EDT, Lee Revell said:
>
> > How do you expect application developers to handle not being able to
> > count on the resolution of nanosleep()? Currently they can at least
> > assume 10ms on 2.4, 1ms on 2.6. Seems to me that if you are no longer
> > guaranteed to be able to sleep 5ms on 2.6, you would just have to
> > busywait. Is it me, or does that way lie madness?
>
> If you're running tickless, wouldn't a 'sleep 5ms' cause a timer event to be
> queued, and we wake up (approx) 5ms later?

Yes, exactly. This is why I think going tickless is a good solution,
and CONFIG_HZ is bad, because with HZ=100 "sleep 5ms" would cause us to
sleep for 10ms.

Lee