lkml.org 
[lkml]   [2005]   [Dec]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [ANNOUNCE] 2.6.15-rc5-hrt2 - hrtimers based high resolution patches
    From
    Date
    On Wed, 2005-12-14 at 08:48 -0500, Steven Rostedt wrote:
    > On Wed, 2005-12-14 at 09:43 +0100, Ingo Molnar wrote:
    > > * Ingo Molnar <mingo@elte.hu> wrote:

    > And going into gdb, I get:
    >
    > (gdb) li *0xc0136b98
    > 0xc0136b98 is in hrtimer_cancel (kernel/hrtimer.c:671).
    > 666 int hrtimer_cancel(struct hrtimer *timer)
    > 667 {
    > 668 for (;;) {
    > 669 int ret = hrtimer_try_to_cancel(timer);
    > 670
    > 671 if (ret >= 0)
    > 672 return ret;
    > 673 }
    > 674 }
    > 675
    >
    > So it may not really be locked, and if I waited a couple of hours, it
    > might actually finish (the test usually takes a couple of minutes to
    > run, and I let it run here for about 20 minutes).
    >
    > Yeah, the above code would be very bad if this happens after preempting
    > the running timer.
    >
    > So the fix to this, in the case of preempting the softirq, that we need
    > to introduce some wait queue that will allow processes to wait for the
    > softirq to finish, and then the softirq will wake up all the processes.

    We had the waitqueue in the ktimer based -rt patches and did not add it
    back.

    tglx


    -
    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: 2005-12-14 14:56    [W:0.023 / U:0.324 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site