On Wed, May 15, 2013 at 07:11:53PM +0200, Peter Zijlstra wrote: > On Wed, May 15, 2013 at 06:59:15PM +0200, Peter Zijlstra wrote: > > 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(). > > Found them: > > 1364991694-5876-1-git-send-email-eran...@google.com > > Looks like they were stuck in my inbox and never applied, so I just did. > They should appear in tip soonish.
That was easy. Next problem! :-p Thanks Peter! Cheers, Don -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
