From 48cf76f7104f655bbd48a75c7759dce82c3e1ab6 Mon Sep 17 00:00:00 2001 From: Torben Hohn Date: Thu, 27 Jan 2011 15:59:05 +0100 Subject: [PATCH] time: Provide get_xtime_and_monotonic_offset() The hrtimer code accesses timekeeping variables under xtime_lock. Provide a sensible accessor function and use it. [ tglx: Removed the conditionals, unused variable, fixed codingstyle and massaged changelog ] Signed-off-by: Torben Hohn Cc: Peter Zijlstra Cc: johnstul@us.ibm.com Cc: yong.zhang0@gmail.com Cc: hch@infradead.org LKML-Reference: <20110127145905.23248.30458.stgit@localhost> Signed-off-by: Thomas Gleixner --- include/linux/time.h | 1 + kernel/hrtimer.c | 13 ++----------- kernel/time/timekeeping.c | 16 ++++++++++++++++ 3 files changed, 19 insertions(+), 11 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index 86a9c487fdd8..4007a12a1b50 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -127,6 +127,7 @@ struct timespec current_kernel_time(void); struct timespec __current_kernel_time(void); /* does not take xtime_lock */ struct timespec __get_wall_to_monotonic(void); /* does not take xtime_lock */ struct timespec get_monotonic_coarse(void); +void get_xtime_and_monotonic_offset(struct timespec *xtim, struct timespec *wtom); #define CURRENT_TIME (current_kernel_time()) #define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 }) diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 0c8d7c048615..57c4d33c9a9d 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -85,13 +85,8 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) { ktime_t xtim, tomono; struct timespec xts, tom; - unsigned long seq; - do { - seq = read_seqbegin(&xtime_lock); - xts = __current_kernel_time(); - tom = __get_wall_to_monotonic(); - } while (read_seqretry(&xtime_lock, seq)); + get_xtime_and_monotonic_offset(&xts, &tom); xtim = timespec_to_ktime(xts); tomono = timespec_to_ktime(tom); @@ -612,15 +607,11 @@ static void retrigger_next_event(void *arg) { struct hrtimer_cpu_base *base; struct timespec realtime_offset, wtm; - unsigned long seq; if (!hrtimer_hres_active()) return; - do { - seq = read_seqbegin(&xtime_lock); - wtm = __get_wall_to_monotonic(); - } while (read_seqretry(&xtime_lock, seq)); + get_xtime_and_monotonic_offset(&realtime_offset, &wtm); set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec); base = &__get_cpu_var(hrtimer_bases); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index c1a178ca0f50..c50aaf6cd01d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -958,3 +958,19 @@ void do_timer(unsigned long ticks) update_wall_time(); calc_global_load(ticks); } + +/** + * get_xtime_and_monotonic_offset() - get xtime and wall_to_monotonic + * @xtim: pointer to timespec to be set with xtime + * @wtom: pointer to timespec to be set with wall_to_monotonic + */ +void get_xtime_and_monotonic_offset(struct timespec *xtim, struct timespec *wtom) +{ + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + *xtim = xtime; + *wtom = wall_to_monotonic; + } while (read_seqretry(&xtime_lock, seq)); +}