lkml.org 
[lkml]   [2009]   [Feb]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: cpuinfo shows wrong MHz value
    Date
    Am Sonntag, 15. Februar 2009 schrieben Sie:
    > Can you check whether or not you were also using p4-clockmode with the
    > last kernel that did show correct values? The same grep command should
    > show this.

    The last kernel that was working correct was 2.6.24 (here the output from
    2.6.24.6):

    affected_cpus:0
    cpuinfo_cur_freq:1600000
    cpuinfo_max_freq:1600000
    cpuinfo_min_freq:400000
    scaling_available_frequencies:400000 600000 800000 1000000 1200000 1400000
    1600000
    scaling_available_governors:conservative ondemand userspace powersave
    performance
    scaling_cur_freq:1600000
    scaling_driver:p4-clockmod
    scaling_governor:performance
    scaling_max_freq:1600000
    scaling_min_freq:400000
    root@jako:/sys/devices/system/cpu/cpu0/cpufreq> uname -a
    Linux jako 2.6.24.6 #1 PREEMPT Tue Feb 17 20:33:58 CET 2009 i686 GNU/Linux

    The log output is somewhat limited, because I forgot to enable debugging:

    root@jako:/sys> dmesg | grep clock
    Time: tsc clocksource has been installed.
    intel8x0_measure_ac97_clock: measured 55906 usecs
    intel8x0: measured clock 71 rejected
    intel8x0: clocking to 48000
    p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available

    Here is the output from 2.6.28.5 and debug info enabled:
    root@jako:~> dmesg | grep clock
    intel8x0_measure_ac97_clock: measured 55894 usecs
    intel8x0: measured clock 71 rejected
    intel8x0: clocking to 48000
    p4-clockmod: P4/Xeon(TM) CPU On-Demand Clock Modulation available

    It looks like the debug code does not provide more information.

    > It would also help to know which kernel version was the last working one.
    > You mentioned 2.6.26, but with some uncertainty. Can you check for 2.6.26
    > and possibly for 2.6.27?

    I was wrong, it was working long ago with kernel 2.6.24, sorry.

    > Note that p4-clockmode does not really help with power saving, but only
    > with thermal management (prevention of overheating). Possibly the
    > speedstep or acpi-cpufreq modules will work better for you, but it can
    > also be they don't support your processor.

    Yes, I know. I just installed it to play with it and now I'm using the
    performance governor all the time which disables frequency modulation.

    > That does not mean this issue should not be looked into of course.

    I can simply unload the module but a fix would be appreciated as well :)

    regards,
    Jörg
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2009-02-18 20:57    [W:0.034 / U:32.880 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site