[lkml]   [2004]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch

    * Andrew Morton <> wrote:

    > > Should I try ext3?
    > ext3 is certainly better than that, but still has a couple of
    > potential problem spots. ext2 is probably the best at this time.

    with the voluntary-preempt patch applied ext3 is below ~500 usecs for
    all things i tried on a 2GHz CPU. Without the patch i can trigger
    latencies up to milliseconds (even with CONFIG_PREEMPT) by triggering a
    bigger commit stream via some large file write or a cached du / causing
    a stream of atime updates. (I very much suspect that all other
    journalled filesystems have similar problems and they'll need
    measurements and fixing just like ext3 does.)

    another bigger problem area is the VM - see my patch for details.
    pagetable zapping and page reclaim are both problematic and need fixups
    even under CONFIG_PREEMPT. Doing a simple 'make -j' kernel build that
    hits swap triggers these easily. (after applying my patch the latencies
    go below 1msec even with a 'make -j' overload.)

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 14:04    [W:0.020 / U:6.124 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site