Re: Timekeeping hosed by factor 3, high lapic[01] interrupt rates

From: Jens Schweikhardt (schweikh_at_schweikhardt.net)
Date: 06/28/05

  • Next message: John Baldwin: "Re: Timekeeping hosed by factor 3, high lapic[01] interrupt rates" 
    Date: Tue, 28 Jun 2005 23:07:49 +0200
To: John Baldwin <jhb@FreeBSD.org>

    John et al,

    # Forget SMP and go back to UP for now. Turn off ntpd if you are using it, then
    # do something like this:
    #
    # # ntpdate ntp.xxxx ; sleep 10 ; ntpdate ntp.xxxx
    #
    # And try it both with the timecounter set to TSC and with the timecounter set
    # to i8254.

    Here we go, kernel with your second patch, boot with kern.smp.disabled=1.

    Script started on Tue Jun 28 22:53:10 2005
    # /etc/rc.d/ntpd stop
    Stopping ntpd.
    # sysctl kern.smp.disabled
    kern.smp.disabled: 1
    # sysctl -a|grep timec
    kern.timecounter.stepwarnings: 0
    kern.timecounter.nbinuptime: 116095
    kern.timecounter.nnanouptime: 0
    kern.timecounter.nmicrouptime: 670
    kern.timecounter.nbintime: 902
    kern.timecounter.nnanotime: 24
    kern.timecounter.nmicrotime: 880
    kern.timecounter.ngetbinuptime: 410
    kern.timecounter.ngetnanouptime: 24
    kern.timecounter.ngetmicrouptime: 2337
    kern.timecounter.ngetbintime: 0
    kern.timecounter.ngetnanotime: 0
    kern.timecounter.ngetmicrotime: 5
    kern.timecounter.nsetclock: 2
    kern.timecounter.hardware: TSC
    kern.timecounter.choice: TSC(800) i8254(0) dummy(-1000000)
    kern.timecounter.tick: 1
    kern.timecounter.smp_tsc: 0
    # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103
    28 Jun 22:54:31 ntpdate[606]: adjust time server 192.53.103.103 offset 0.275702 sec
    28 Jun 22:54:41 ntpdate[608]: adjust time server 192.53.103.103 offset 0.267708 sec
    # sysctl kern.timecounter.hardware=i8254
    kern.timecounter.hardware: TSC -> i8254
    # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103
    28 Jun 22:55:16 ntpdate[621]: step time server 192.53.103.103 offset 8.265734 sec
    28 Jun 22:56:16 ntpdate[623]: step time server 192.53.103.103 offset 49.488049 sec
    # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103
    28 Jun 22:56:50 ntpdate[624]: step time server 192.53.103.103 offset 27.732229 sec
    28 Jun 22:57:49 ntpdate[626]: step time server 192.53.103.103 offset 48.679758 sec
    # sysctl kern.timecounter.hardware=TSC
    kern.timecounter.hardware: i8254 -> TSC
    # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103
    28 Jun 22:57:59 ntpdate[628]: step time server 192.53.103.103 offset 2.417985 sec
    28 Jun 22:58:10 ntpdate[630]: adjust time server 192.53.103.103 offset -0.008257 sec
    # ntpdate 192.53.103.103; sleep 10; ntpdate 192.53.103.103
    28 Jun 22:58:23 ntpdate[631]: adjust time server 192.53.103.103 offset -0.005786 sec
    28 Jun 22:58:33 ntpdate[633]: adjust time server 192.53.103.103 offset -0.004015 sec
    #
    Script done on Tue Jun 28 22:58:38 2005

    Regards,

            Jens 

    -- 
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)
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  • Next message: John Baldwin: "Re: Timekeeping hosed by factor 3, high lapic[01] interrupt rates"

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