On Thu, Feb 16, 2017 at 08:34:45PM +0100, Thomas Gleixner wrote: > On Thu, 16 Feb 2017, Frederic Weisbecker wrote: > > On Thu, Feb 16, 2017 at 10:20:14AM -0800, Linus Torvalds wrote: > > > On Thu, Feb 16, 2017 at 10:13 AM, Frederic Weisbecker > > > <fweis...@gmail.com> wrote: > > > > > > > > I haven't followed the discussion but this patch has a known issue > > > > which is fixed > > > > with: > > > > 7bdb59f1ad474bd7161adc8f923cdef10f2638d1 > > > > "tick/nohz: Fix possible missing clock reprog after tick soft > > > > restart" > > > > > > > > I hope this fixes your issue. > > > > > > No, Pavel saw the problem with rc8 too, which already has that fix. > > > > > > So I think we'll just need to revert that original patch (and that > > > means that we have to revert the commit you point to as well, since > > > that ->next_tick field was added by the original commit). > > > > Aw too bad, but indeed that late we don't have the choice. > > Hint: Look for CPU hotplug interaction of these patches. I bet something > becomes stale when the CPU goes down and does not get reset when it comes > back online.
Indeed I should check that. But Pavel is seeing this on boot, where the only hotplug operations that happen are CPU UP without preceding CPU DOWN that may have retained stale values. I think the value of ts->next_tick should be initially 0 for all CPUs. So perhaps that 0 value confuses stuff. But looking at the code I don't see how. It maybe something more subtle. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
