Messages in this thread Patch in this message | | | From | John Stultz <> | Subject | [PATCH 6/7] time: Reduce timekeeper read lock hold time | Date | Mon, 27 Feb 2012 16:29:33 -0800 |
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Now that timekeeper updates are done with a shadow copy, we can reduce the readlock hold time to only the update.
CC: Thomas Gleixner <tglx@linutronix.de> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> --- kernel/time/timekeeping.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index ebfb037..5a444b8 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1062,7 +1062,6 @@ static void update_wall_time(void) s64 remainder; spin_lock_irqsave(&timekeeper.wlock, flags); - write_seqcount_begin(&timekeeper.rlock); /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) @@ -1145,13 +1144,18 @@ static void update_wall_time(void) second_overflow(); } - + write_seqcount_begin(&timekeeper.rlock); + /* + * We have to store rlock back to tk, otherwise we'll + * corrupt the timeekeerp.rlock when we copy over timekeeper + */ + tk.rlock = timekeeper.rlock; timekeeper = tk; timekeeper.clock->cycle_last = timekeeper.cycle_last; timekeeping_update(&timekeeper, false); + write_seqcount_end(&timekeeper.rlock); out: - write_seqcount_end(&timekeeper.rlock); spin_unlock_irqrestore(&timekeeper.wlock, flags); } -- 1.7.3.2.146.gca209
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