Re: [patch] voluntary-preempt-2.6.8.1-P5

Lee Revell
2004-08-21T09:16:29Z

On Sat, 2004-08-21 at 05:13, Ingo Molnar wrote:
> * Lee Revell <rlrevell@joe-job.com> wrote:
>
> > On Fri, 2004-08-20 at 09:30, Ingo Molnar wrote:
> >
> > > - reduce ZAP_BLOCK_SIZE to 16 when vp != 0. This pushes the exit
> > > latency down to below 100 usecs on Lee Revell's box.
> > >
> >
> > Almost:
> >
> > http://krustophenia.net/testresults.php?dataset=2.6.8.1-P6#/var/www/2.6.8.1-P6/trace8.txt
>
> i suspect if you turn off tracing (or disable it in the kernel
> completely) then you'd see below-100 usec latencies here. A trace entry
> costs ~0.3 usecs on your box, so this 50-entry trace has roughly 15
> usecs of tracing overhead :-)
>

FWIW, I did see one of these over 200 usecs.

Lee