From 03a90b9a6f7eec70edde4eb1f88fa8a5c058d85e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 17 Jul 2012 13:33:54 -0400 Subject: timekeeping: Maintain ktime_t based offsets for hrtimers This is a backport of 5b9fe759a678e05be4937ddf03d50e950207c1c0 We need to update the hrtimer clock offsets from the hrtimer interrupt context. To avoid conversions from timespec to ktime_t maintain a ktime_t based representation of those offsets in the timekeeper. This puts the conversion overhead into the code which updates the underlying offsets and provides fast accessible values in the hrtimer interrupt. Signed-off-by: Thomas Gleixner Signed-off-by: John Stultz Reviewed-by: Ingo Molnar Acked-by: Peter Zijlstra Acked-by: Prarit Bhargava Link: http://lkml.kernel.org/r/1341960205-56738-4-git-send-email-johnstul@us.ibm.com Signed-off-by: Thomas Gleixner Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- kernel/time/timekeeping.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 92014744e524..d6477733fc04 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -161,11 +161,26 @@ static struct timespec xtime __attribute__ ((aligned (16))); static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); static struct timespec total_sleep_time; +/* Offset clock monotonic -> clock realtime */ +static ktime_t offs_real; + +/* Offset clock monotonic -> clock boottime */ +static ktime_t offs_boot; + /* * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ static struct timespec raw_time; +/* must hold write on xtime_lock */ +static void update_rt_offset(void) +{ + struct timespec tmp, *wtm = &wall_to_monotonic; + + set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec); + offs_real = timespec_to_ktime(tmp); +} + /* must hold write on xtime_lock */ static void timekeeping_update(bool clearntp) { @@ -173,6 +188,7 @@ static void timekeeping_update(bool clearntp) timekeeper.ntp_error = 0; ntp_clear(); } + update_rt_offset(); update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult); } @@ -587,6 +603,7 @@ void __init timekeeping_init(void) } set_normalized_timespec(&wall_to_monotonic, -boot.tv_sec, -boot.tv_nsec); + update_rt_offset(); total_sleep_time.tv_sec = 0; total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -595,6 +612,12 @@ void __init timekeeping_init(void) /* time in seconds when suspend began */ static struct timespec timekeeping_suspend_time; +static void update_sleep_time(struct timespec t) +{ + total_sleep_time = t; + offs_boot = timespec_to_ktime(t); +} + /** * __timekeeping_inject_sleeptime - Internal function to add sleep interval * @delta: pointer to a timespec delta value @@ -606,7 +629,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta) { xtime = timespec_add(xtime, *delta); wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta); - total_sleep_time = timespec_add(total_sleep_time, *delta); + update_sleep_time(timespec_add(total_sleep_time, *delta)); } -- cgit v1.2.3