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 <t...@linutronix.de>
Cc: Preeti U Murthy <pre...@linux.vnet.ibm.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Viresh Kumar <viresh.ku...@linaro.org>
Cc: Marcelo Tosatti <mtosa...@redhat.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@kernel.org>
Reported-by: Jeremiah Mahler <jmmah...@gmail.com>
Signed-off-by: John Stultz <john.stu...@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
--
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