Re: 1kHz noise from C3 sleep

On Thu, 20 Oct 2005 11:25:59 -0700
Nate Lawson <nate_at_root.org> wrote:

> Alexander Leidinger wrote:
> > Nate Lawson <nate_at_root.org> wrote:
> > 
> > [Moving to -current]
> > 
> >>> I wonder if moving to HZ=1000 on amd64 and i386 was really all that good
> >>> of an idea.  Having preemption in the kernel means that ithreads can run
> >>> right away instead of having to wait for a tick, and various fixes to
> >>> 4BSD in the past year have eliminated bugs that would make the CPU wait
> >>> for up to a tick to schedule a thread.  So all we're getting now is a
> >>> 10x increase in scheduler overhead, including reading the timecounters.
> >>
> >>
> >> I use hz=100 on my systems due to the 1 khz noise from C3 sleep. 
> >> Windows has the same problem.
> > 
> > 
> > My laptop makes noises when being (more or less) idle (I think I enabled
> > C3...). Does this mean I should try to change HZ?
> 
> Sure, you can do it from a tunable (kern.hz I think), you don't have to 
> recompile.

No, a HZ of 100 doesn't work, the laptop still makes noises. And it
only has C2, no C3...

Bye,
Alexander.

-- 
                      Loose bits sink chips.

http://www.Leidinger.net                       Alexander _at_ Leidinger.net
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