On Fri, Jun 23, 2017 at 11:50:25PM +0200, Thomas Gleixner wrote: > On Fri, 23 Jun 2017, Don Zickus wrote: > > Hmm, all this work for a temp fix. Kan, how much longer until the real fix > > of having perf count the right cycles? > > Quite a while. The approach is wilfully breaking the user space ABI, which > is not going to happen. > > And there is a simpler solution as well, as I said here: > > http://lkml.kernel.org/r/alpine.DEB.2.20.1706221730520.1885@nanos Hi Thomas, So, you are saying instead of slowing down the perf counter, speed up the hrtimer to sample more frequently like so: diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 03e0b69..8ff49de 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -160,7 +160,7 @@ static void set_sample_period(void) * and hard thresholds) to increment before the * hardlockup detector generates a warning */ - sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5); + sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 10); } /* Commands for resetting the watchdog */ That is another way of doing it. It just hits all the arches. It does seem cleaner as the watchdog_thresh value still retains it correct meaning. Are the laptop folks going to yell at me some more for waking their systems up more? :-) Cheers, Don