Re: 1kHz noise from C3 sleep

From: Alexander Leidinger (Alexander_at_Leidinger.net)
Date: 10/23/05

  • Next message: Stefan Ehmann: "Re: ipfw uid/gid rules and mpsafenet (Re: PREEMPTION still unusable with 6.0-RC1)"
    Date: Sun, 23 Oct 2005 12:13:38 +0200
    To: Nate Lawson <nate@root.org>
    
    

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

    > Alexander Leidinger wrote:
    > > Nate Lawson <nate@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 @ Leidinger.net
      GPG fingerprint = C518 BC70 E67F 143F BE91  3365 79E2 9C60 B006 3FE7
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  • Next message: Stefan Ehmann: "Re: ipfw uid/gid rules and mpsafenet (Re: PREEMPTION still unusable with 6.0-RC1)"