diff options
| author | John Stultz <johnstul@us.ibm.com> | 2012-07-17 18:05:29 -0400 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-10-07 23:37:06 +0200 |
| commit | 40821c765eb339c04407c7382c9edbb8a7d340e3 (patch) | |
| tree | 29d4190a1cc694a59adc7661712bea7cbf27476f /include | |
| parent | 9ec72638e59fca1951a65ce68fcf693f7c98ecbf (diff) | |
hrtimer: Provide clock_was_set_delayed()
This is a backport of f55a6faa384304c89cfef162768e88374d3312cb
clock_was_set() cannot be called from hard interrupt context because
it calls on_each_cpu().
For fixing the widely reported leap seconds issue it is necessary to
call it from hard interrupt context, i.e. the timer tick code, which
does the timekeeping updates.
Provide a new function which denotes it in the hrtimer cpu base
structure of the cpu on which it is called and raise the hrtimer
softirq. We then execute the clock_was_set() notificiation from
softirq context in run_hrtimer_softirq(). The hrtimer softirq is
rarely used, so polling the flag there is not a performance issue.
[ tglx: Made it depend on CONFIG_HIGH_RES_TIMERS. We really should get
rid of all this ifdeffery ASAP ]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Reported-by: Jan Engelhardt <jengelh@inai.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1341960205-56738-2-git-send-email-johnstul@us.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/hrtimer.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 040b6796ab4d..a7f48af3e343 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -159,6 +159,7 @@ struct hrtimer_clock_base { * and timers * @clock_base: array of clock bases for this cpu * @curr_timer: the timer which is executing a callback right now + * @clock_was_set: Indicates that clock was set from irq context. * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() * @hres_active: State of high resolution mode @@ -171,6 +172,7 @@ struct hrtimer_clock_base { struct hrtimer_cpu_base { spinlock_t lock; struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; + unsigned int clock_was_set; #ifdef CONFIG_HIGH_RES_TIMERS ktime_t expires_next; int hres_active; @@ -280,6 +282,8 @@ extern void hrtimer_peek_ahead_timers(void); # define MONOTONIC_RES_NSEC HIGH_RES_NSEC # define KTIME_MONOTONIC_RES KTIME_HIGH_RES +extern void clock_was_set_delayed(void); + #else # define MONOTONIC_RES_NSEC LOW_RES_NSEC @@ -308,6 +312,9 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer) { return 0; } + +static inline void clock_was_set_delayed(void) { } + #endif extern ktime_t ktime_get(void); |