From 14a3b6abe98c8f53a13522610c257accef7321df Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Feb 2013 22:51:38 +0000 Subject: [PATCH] timekeeping: Store cycle_last value in timekeeper struct as well For implementing a shadow timekeeper and a split calculation/update region we need to store the cycle_last value in the timekeeper and update the value in the clocksource struct only in the update region. Add the extra storage to the timekeeper. Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz --- include/linux/timekeeper_internal.h | 2 ++ kernel/time/timekeeping.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index a151bd7..c1825eb 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -20,6 +20,8 @@ struct timekeeper { u32 shift; /* Number of clock cycles in one NTP interval. */ cycle_t cycle_interval; + /* Last cycle value (also stored in clock->cycle_last) */ + cycle_t cycle_last; /* Number of clock shifted nano seconds in one NTP interval. */ u64 xtime_interval; /* shifted nano seconds left over when rounding cycle_interval */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index f93f60c..4c276b2d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -101,7 +101,7 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) old_clock = tk->clock; tk->clock = clock; - clock->cycle_last = clock->read(clock); + tk->cycle_last = clock->cycle_last = clock->read(clock); /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; @@ -266,7 +266,7 @@ static void timekeeping_forward_now(struct timekeeper *tk) clock = tk->clock; cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - clock->cycle_last = cycle_now; + tk->cycle_last = clock->cycle_last = cycle_now; tk->xtime_nsec += cycle_delta * tk->mult; -- 2.7.4