lkml.org 
[lkml]   [2004]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [patch] Latency Tracer, voluntary-preempt-2.6.8-rc4-O6

    * James Courtier-Dutton <James@superbug.demon.co.uk> wrote:

    > I have tested this for a day now, and I have noticed problems:
    > 1)
    > kernel syslog gets a record like this:
    > > (default.hotplug/1470): 121 us critical section violates 100 us
    > threshold.

    > and the /proc/latency_trace gets:
    > > preemption latency trace v1.0
    > > -----------------------------
    > > latency: 121 us, entries: 1032 (1032)
    > > process: default.hotplug/1470, uid: 0
    > > nice: -10, policy: 0, rt_priority: 0
    > > =======>
    > > 0.000ms (+0.000ms): page_address (kmap_high)
    > > 0.000ms (+0.000ms): page_slot (page_address)
    > > 0.000ms (+0.000ms): flush_all_zero_pkmaps (kmap_high)
    > > 0.000ms (+0.000ms): set_page_address (flush_all_zero_pkmaps)

    > Could the patch be adjusted to make the syslog and the
    > /proc/latency_trace produce the same output?

    We cannot include the full trace in the syslog - it's possibly thousands
    of lines long.

    > 2)
    > I suspect that there is a problem with reiserfs, but when I detect a
    > momentary hang in the system(mouse stops moving), no latency_trace appears.

    well, the mouse could stop moving for a number of reasons. It's handled
    via the X server and if the X server is preempted (for whatever reason)
    then the mouse pointer isnt updated.

    you could try to change the mouse IRQ to be non-threaded. Also, do you
    have kernel_preemption set to 1? It defaults to 0.

    Ingo
    -
    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: 2005-03-22 14:05    [W:0.022 / U:30.496 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site