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    SubjectRe: [PATCH 1/2] nohz: Disable LOCKUP_DETECTOR when NO_HZ_FULL is enabled
    On Wed, May 15, 2013 at 11:27:02AM -0400, Steven Rostedt wrote:
    > Right now perf requires a tick, not sure exactly why, but you can look
    > at the code in perf_event_task_tick(). Thus if NO_HZ_FULL sees that a
    > perf tick is pending, it won't disable ticks. Unfortunately, the
    > watchdogs, both NMI and soft lockup, use the perf infrastructure to
    > trigger NMIs or interrupts. This adds a perf element on the rotate list
    > and keeps NO_HZ_FULL from *ever* activating.
    >

    Hmm.. Stephane had a bunch of patches converting the rotation thing to
    an hrtimer. I seem to have forgotten what happened to them but I can't
    seem to find them merged.

    I'll go look.

    That leaves the frequency stuff, but the watchdog doesn't use that.

    At which point we could run the watchdog without perf_event_task_tick().
    >


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