diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2011-03-10 18:26:33 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2011-03-10 19:15:58 +0100 |
| commit | 53370d2e8c0382e3e2aa76def93365ed674e7fc7 (patch) | |
| tree | 531ed0d50c452332f5bc1b7d75539f24f532c326 /include/linux/hrtimer.h | |
| parent | 5cd10e7946d28cfc42442fee2e6c757e244d756e (diff) | |
hrtimer: Update hrtimer->state documentation
We changed some of the state bits and combinations thereof over time,
but never updated the documentation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 6bc1804bfbfa..62f500c724f9 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -54,11 +54,13 @@ enum hrtimer_restart { * 0x00 inactive * 0x01 enqueued into rbtree * 0x02 callback function running + * 0x04 timer is migrated to another cpu * * Special cases: * 0x03 callback function running and enqueued * (was requeued on another CPU) - * 0x09 timer was migrated on CPU hotunplug + * 0x05 timer was migrated on CPU hotunplug + * * The "callback function running and enqueued" status is only possible on * SMP. It happens for example when a posix timer expired and the callback * queued a signal. Between dropping the lock which protects the posix timer @@ -67,8 +69,11 @@ enum hrtimer_restart { * as otherwise the timer could be removed before the softirq code finishes the * the handling of the timer. * - * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state to - * preserve the HRTIMER_STATE_CALLBACK bit in the above scenario. + * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state + * to preserve the HRTIMER_STATE_CALLBACK in the above scenario. This + * also affects HRTIMER_STATE_MIGRATE where the preservation is not + * necessary. HRTIMER_STATE_MIGRATE is cleared after the timer is + * enqueued on the new cpu. * * All state transitions are protected by cpu_base->lock. */ @@ -376,8 +381,9 @@ extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); extern ktime_t hrtimer_get_next_event(void); /* - * A timer is active, when it is enqueued into the rbtree or the callback - * function is running. + * A timer is active, when it is enqueued into the rbtree or the + * callback function is running or it's in the state of being migrated + * to another cpu. */ static inline int hrtimer_active(const struct hrtimer *timer) { |