On Wed, Jun 07, 2017 at 04:14:03PM +0200, Frederic Weisbecker wrote: > On Wed, Jun 07, 2017 at 04:17:41AM +0000, Levin, Alexander (Sasha Levin) wrote: > > > Thanks Sasha! > > > > > > I couldn't reproduce it, that config boots fine on my kvm. > > > Would you have the time to dump some traces for me? > > > > > > I'd need you to add this boot option: trace_event=hrtimer_cancel,hrtimer_start,hrtimer_expire_entry > > > And boot your kernel with the below patch. This will dump the timer traces to your console. > > > I would be very interested in the resulting console dump file. > > > > Attached. Let me know if you need anything else. > > Great! So now I can deduce that the problem doesn't come from the nohz code as > ts->next_tick matches the hrtimer deadline. But the dev->next_event from the > clockevent seems to be out of line. > > Sorry to bother you again, but I'm chasing this bug for several weeks now and > you're one of the rare person who can reproduce it. So I may need some more > tracing details. I take payment in beers ;) But really, not a problem. > Here is another version of the debugging patch (not a delta), I added more trace_printk, > namely the places where we set this dev->next_event. Can you please apply the below and do > the dump again? Attached. -- Thanks, Sasha
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