Messages in this thread Patch in this message | | | Date | Fri, 12 Jun 2015 02:31:36 -0700 | From | tip-bot for John Stultz <> | Subject | [tip:timers/core] time: Move clock_was_set_seq update before updating shadow-timekeeper |
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Commit-ID: d151832650ed98961a5650e73e85c349ad7839cb Gitweb: http://git.kernel.org/tip/d151832650ed98961a5650e73e85c349ad7839cb Author: John Stultz <john.stultz@linaro.org> AuthorDate: Thu, 11 Jun 2015 15:54:53 -0700 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Fri, 12 Jun 2015 10:56:20 +0200
time: Move clock_was_set_seq update before updating shadow-timekeeper
It was reported that 868a3e915f7f5eba (hrtimer: Make offset update smarter) was causing timer problems after suspend/resume.
The problem with that change is the modification to clock_was_set_seq in timekeeping_update is done prior to mirroring the time state to the shadow-timekeeper. Thus the next time we do update_wall_time() the updated sequence is overwritten by whats in the shadow copy.
This patch moves the shadow-timekeeper mirroring to the end of the function, after all updates have been made, so all data is kept in sync.
(This patch also affects the update_fast_timekeeper calls which were also problematically done prior to the mirroring).
Reported-and-tested-by: Jeremiah Mahler <jmmahler@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1434063297-28657-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/time/timekeeping.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 90ed5db..849b932 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -585,15 +585,19 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action) update_vsyscall(tk); update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); - if (action & TK_MIRROR) - memcpy(&shadow_timekeeper, &tk_core.timekeeper, - sizeof(tk_core.timekeeper)); - update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); if (action & TK_CLOCK_WAS_SET) tk->clock_was_set_seq++; + /* + * The mirroring of the data to the shadow-timekeeper needs + * to happen last here to ensure we don't over-write the + * timekeeper structure on the next update with stale data + */ + if (action & TK_MIRROR) + memcpy(&shadow_timekeeper, &tk_core.timekeeper, + sizeof(tk_core.timekeeper)); } /**
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