diff options
| author | Viresh Kumar <viresh.kumar@linaro.org> | 2015-03-25 11:57:45 +0530 |
|---|---|---|
| committer | Gary S. Robertson <gary.robertson@linaro.org> | 2015-07-22 16:06:19 -0500 |
| commit | 912733d1149505d904ba713a0041bc98be882f8b (patch) | |
| tree | 046840a272e4f52702353491ebbae181f33ed7e3 | |
| parent | 456d70e9bddc5807b1663d04b0e9c7045f6157ab (diff) | |
hrtimer: update timer->state with 'pinned' information
'Pinned' information would be required in migrate_hrtimers() now, as we can
migrate non-pinned timers away without a hotplug (i.e. with cpuset.quiesce). And
so we may need to identify pinned timers now, as we can't migrate them.
This patch reuses the timer->state variable for setting this flag as there were
enough number of free bits available in this variable. And there is no point
increasing size of this struct by adding another field.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[forward port to 3.18]
Signed-off-by: Santosh Shukla <santosh.shukla@linaro.org>
| -rw-r--r-- | include/linux/hrtimer.h | 3 | ||||
| -rw-r--r-- | kernel/time/hrtimer.c | 12 |
2 files changed, 13 insertions, 2 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index a036d058a249..33085e9d3a4a 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -55,6 +55,7 @@ enum hrtimer_restart { * 0x01 enqueued into rbtree * 0x02 callback function running * 0x04 timer is migrated to another cpu + * 0x08 timer is pinned to a cpu * * Special cases: * 0x03 callback function running and enqueued @@ -81,6 +82,8 @@ enum hrtimer_restart { #define HRTIMER_STATE_ENQUEUED 0x01 #define HRTIMER_STATE_CALLBACK 0x02 #define HRTIMER_STATE_MIGRATE 0x04 +#define HRTIMER_PINNED_SHIFT 3 +#define HRTIMER_STATE_PINNED (1 << HRTIMER_PINNED_SHIFT) /** * struct hrtimer - the basic hrtimer structure diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 210b84882935..cc1b5d32ae83 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -882,7 +882,11 @@ static void __remove_hrtimer(struct hrtimer *timer, if (!timerqueue_getnext(&base->active)) base->cpu_base->active_bases &= ~(1 << base->index); out: - timer->state = newstate; + /* + * We need to preserve PINNED state here, otherwise we may end up + * migrating pinned hrtimers as well. + */ + timer->state = newstate | (timer->state & HRTIMER_STATE_PINNED); } /* @@ -952,6 +956,10 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, timer_stats_hrtimer_set_start_info(timer); + /* Update pinned state */ + timer->state &= ~HRTIMER_STATE_PINNED; + timer->state |= !!(mode & HRTIMER_MODE_PINNED) << HRTIMER_PINNED_SHIFT; + leftmost = enqueue_hrtimer(timer, new_base); if (!leftmost) { @@ -1227,7 +1235,7 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) * hrtimer_start_range_ns() or in hrtimer_interrupt() */ if (restart != HRTIMER_NORESTART) { - BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); + BUG_ON(!(timer->state & HRTIMER_STATE_CALLBACK)); enqueue_hrtimer(timer, base); } |