Re: [ck] Re: 2.6.15-ck1

[Con Kolivas <kernel@kolivas.org>]

On Thursday 05 January 2006 17:42, Vojtech Pavlik wrote:
> On Thu, Jan 05, 2006 at 02:22:37AM +0100, Andi Kleen wrote:
> > Arjan van de Ven <arjan@infradead.org> writes:
> > > sounds like we need some sort of profiler or benchmarker or at least a
> > > tool that helps finding out which timers are regularly firing, with the
> > > aim at either grouping them or trying to reduce their disturbance in
> > > some form.
> >
> > I did one some time ago for my own noidletick patch. Can probably dig
> > it out again. It just profiled which timers interrupted idle.
> >
> > Executive summary for my laptop: worst was the keyboard driver (it ran
> > some polling driver to work around some hardware bug, but fired very
> > often) , followed by the KDE desktop (should be mostly
> > fixed now, I complained) and the X server and some random kernel
> > drivers.
> >
> > I haven't checked recently if keyboard has been fixed by now.
>
> It's not. At this moment it's impossible to remove without significant
> surgery to the driver, because it'd prevent hotplugging and many KVMs
> from working.
>
> I can rather easily make the timer frequency variable. Would be 1 second
> idle ticks OK?

Sure. The lower the better, and HZ with dynticks bottoms out at 14HZ.

Cheers,
Con