lkml.org 
[lkml]   [2012]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    Subject[PATCH RT 0/9][RFC] rt: Fix hotplugging and other nasties
    On both 3.0-rt and 3.2-rt I ran a stress test on CPU hotplug and they
    both failed miserably. These bugs also show themselves on suspend.

    After spending 5 long days debugging this, and finding lots of bugs
    I have a patch series that makes the CPU hot plugging rather stable.

    The first few patches fix other broken RT features that were discovered
    while debugging hotplug.

    Patch 7 is a rework of how RT handles taking down a CPU. There were
    several corner cases that the original approach failed on, and this
    rework seems to cover them now.

    Patch 8 and 9 revert the rework that was done on workqueue for RT.
    Yes, letting workqueues play games with THREAD_BOUND is bad, but
    the fixes introduced several more races that were very hard to fix.
    Every fix seemed to produce a new race, and it was a bad game of
    cat and mouse running around a goose hunt whacking moles!

    Since the rework of the CPU down code no longer had issues with
    workqueue messing with THREAD_BOUND, reverting the patches that did
    the rework of workqueues fixed the bugs that I was hitting.

    Lets fix CPU hotplug today, and leave the redesign of workqueues
    for another day.

    Comments,

    -- Steve



    \
     
     \ /
      Last update: 2012-03-01 20:09    [W:0.020 / U:31.384 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site