[PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-12 Thread Frederic Weisbecker
The sanity check ensuring that the tick expiry cache (ts->next_tick) is actually in sync with the hardware clock (dev->next_event) makes the wrong assumption that the clock can't be programmed later than the hrtimer deadline. In fact the clock hardware can be programmed later on some conditions su

Re: [PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-09 Thread Frederic Weisbecker
On Fri, Jun 09, 2017 at 12:13:49PM +, Levin, Alexander (Sasha Levin) wrote: > On Fri, Jun 09, 2017 at 02:48:57AM +0200, Frederic Weisbecker wrote: > > On Thu, Jun 08, 2017 at 10:13:38PM +, Levin, Alexander (Sasha Levin) > > wrote: > > > On Thu, Jun 08, 2017 at 09:07:05PM +0200, Frederic We

Re: [PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-09 Thread Peter Zijlstra
On Fri, Jun 09, 2017 at 12:13:49PM +, Levin, Alexander (Sasha Levin) wrote: > On Fri, Jun 09, 2017 at 02:48:57AM +0200, Frederic Weisbecker wrote: > > On Thu, Jun 08, 2017 at 10:13:38PM +, Levin, Alexander (Sasha Levin) > > wrote: > > > On Thu, Jun 08, 2017 at 09:07:05PM +0200, Frederic We

Re: [PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-09 Thread Levin, Alexander (Sasha Levin)
On Fri, Jun 09, 2017 at 02:48:57AM +0200, Frederic Weisbecker wrote: > On Thu, Jun 08, 2017 at 10:13:38PM +, Levin, Alexander (Sasha Levin) > wrote: > > On Thu, Jun 08, 2017 at 09:07:05PM +0200, Frederic Weisbecker wrote: > > > Awesome, these traces have been very helpful! So now I think I get

Re: [PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-08 Thread Frederic Weisbecker
On Thu, Jun 08, 2017 at 10:13:38PM +, Levin, Alexander (Sasha Levin) wrote: > On Thu, Jun 08, 2017 at 09:07:05PM +0200, Frederic Weisbecker wrote: > > Awesome, these traces have been very helpful! So now I think I get what's > > going on. > > Can you please test the following fix? > > With th

[PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-08 Thread Levin, Alexander (Sasha Levin)
On Thu, Jun 08, 2017 at 09:07:05PM +0200, Frederic Weisbecker wrote: > Awesome, these traces have been very helpful! So now I think I get what's > going on. > Can you please test the following fix? With the patch, I hit the warning early on boot: [1.423727] clocksource: Switched to clocksour

[PATCH] nohz: Fix spurious warning when hrtimer and clockevent get out of sync

2017-06-08 Thread Frederic Weisbecker
these traces have been very helpful! So now I think I get what's going on. Can you please test the following fix? Thanks a lot! --- >From 604a46c3e821c61411cee2205fa1cb65e5b04174 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 8 Jun 2017 16:32:58 +0200 Subject: [PATCH] n