Messages in this thread Patch in this message | | | From | John Stultz <> | Subject | [PATCH 1/5] time: Move clock_was_set_seq update to before we update the shadow-timekeeper | Date | Thu, 11 Jun 2015 15:54:53 -0700 |
| |
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).
Cc: Thomas Gleixner <tglx@linutronix.de> 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> Cc: Ingo Molnar <mingo@kernel.org> Reported-by: Jeremiah Mahler <jmmahler@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> --- 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)); } /** -- 1.9.1
| |