[lkml]   [2008]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [Bug #11516] severe performance degradation on x86_64 going from 2.6.26-rc9 -> 2.6.27-rc5
    On Tue, 23 Sep 2008, Jason Vas Dias wrote:

    > CPU Frequency switching is completely disabled both when
    > powernow-k8 (the correct cpufreq module for my x86_64 AMD TL-64x2
    > 2.2GHz CPU) is installed as a module or is built-in , and the CPU
    > frequency remains at its lowest setting; attempts to modify
    > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq and
    > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed are not
    > honored, even though /sys/devices/system/cpu/cpu0/cpufreq/governor
    > is "userspace" and scaling_min_freq < scaling_setspeed >
    > scaling_max_freq .
    > I see no messages from powernow-k8 indicating that it is aware it
    > was unable to set the speed, though I do see a message if I attempt
    > to set an invalid speed (eg 600000) .
    > With 2.6.26-rc9, I get a default CPU clock frequency of 2200000 ;
    > with 2.6.27-rc6, it becomes 800000 and is not switchable. For some
    > reason, powernow-k8 does not autoload with UDEV; but I don't really
    > need it if the speed is already set to its highest level.
    > On 2.6.27-rc6. after it manages to boot, any low-latency drivers
    > time out (eg. USB, Terminal, Keyboard, Network) and the machine does
    > not get through the boot-up sequence without becoming overloaded by
    > the kernel's debugging log messages - neither the network , the
    > terminal or the keyboard work usably.
    > Building a kernel with USB completely disabled and turning off
    > debug log messages allows the machine to boot (after @ 15 minutes)
    > but the speed is still at its lowest setting and cannot be changed.

    I have to admit that I'm confused.

    The dmesg output
    [ 0.000000] Linux version 2.6.27-rc6.jvd ...
    [ 26.204477] hub 3-0:1.0: state 7 ports 2 chg 0000 evt 0000

    says 26 seconds up to the point where user space should start. Also
    USB is active in that log and I dont see timeout messages at all.

    I have a hard time to connect this to your problem description
    (timeouts, USB off, 15 minutes)

    Can you please shed some light on this ?

    > Also, 2.6.27-rc6 is unable to reboot the machine: it can put the
    > machine into the "HALT" state, with nothing displayed on the screen,
    > but the machine does not power-off until manual reset with the
    > power-button. Then, after the machine has powered-down, it cannot be
    > powered up until the power-on button is depressed for at least two
    > sections an released TWICE in a row.

    Len, any opinon on this:

    [ 0.000000] ACPI Error (tbfadt-0453): 32/64X address mismatch in "Pm2ControlBlock":
    [00008800] [0000000000008100], using 64X [20080609]



     \ /
      Last update: 2008-09-27 11:27    [W:0.022 / U:19.328 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site