so much clock interrupts?!

[Kris Kennaway]

On Fri, Nov 25, 2005 at 07:45:03AM +0100, Markus Trippelsdorf wrote:
> On Thu, Nov 24, 2005 at 03:43:59PM -0500, Kris Kennaway wrote:
> > On Thu, Nov 24, 2005 at 07:40:40AM +0000, Markus Trippelsdorf wrote:
> > > On 2005-11-24, Wojciech Puchar <wojtek at tensor.3miasto.net> wrote:
> > > > that's what i see in systat with FreeBSD 6.0/i386-SMP
> > > >
> > > >
> > > >        540      534   99                                   pdwak  2000 cpu0: time
> > > >                                                      16825 pdpgs  2000 cpu1: time
> > > >
> > > >
> > > > on FreeBSD 5.3 live CD i have 100 not 2000 times per second
> > > >
> > > > isn't it too much?!
> > > 
> > > Yes it is.
> > > That's why I have kern.hz="100" in my /boot/loader.conf .
> > 
> > Have you been able to measure a performance benefit from reducing it?
> > Have you shown that reducing it does not cause your performance to
> > *drop*?  It was increased for a reason..it actually increases
> > performance on some workloads.
> > 
> Yes, I guess it increases performance on a high throughput webserver or
> router that uses polling. 
> But on the Desktop it only increases the overhead without any benefits
> at all. 2000 interrupts per second per core for the timer is a 
> ridiculous high number and I reduce it simply for aesthetic reasons.
> This may be a religious issue and everyone should use what he or she
> seems fitting.

You should do what makes you feel happy, of course :)

Kris
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