Messages in this thread | | | Date | Sun, 22 Apr 2012 21:01:43 -0700 | From | mark gross <> | Subject | Re: [PATCH 2/8] PM / Sleep: Use wait queue to signal "no wakeup events in progress" |
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On Sun, Apr 22, 2012 at 11:20:39PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@sisk.pl> > > The current wakeup source deactivation code doesn't do anything when > the counter of wakeup events in progress goes down to zero, which > requires pm_get_wakeup_count() to poll that counter periodically. > Although this reduces the average time it takes to deactivate a > wakeup source, it also may lead to a substantial amount of unnecessary > polling if there are extended periods of wakeup activity. Thus it > seems reasonable to use a wait queue for signaling the "no wakeup > events in progress" condition and remove the polling. > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > --- > drivers/base/power/wakeup.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > Index: linux/drivers/base/power/wakeup.c > =================================================================== > --- linux.orig/drivers/base/power/wakeup.c > +++ linux/drivers/base/power/wakeup.c > @@ -17,8 +17,6 @@ > > #include "power.h" > > -#define TIMEOUT 100 > - > /* > * If set, the suspend/hibernate code will abort transitions to a sleep state > * if wakeup events are registered during or immediately before the transition. > @@ -52,6 +50,8 @@ static void pm_wakeup_timer_fn(unsigned > > static LIST_HEAD(wakeup_sources); > > +static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); > + > /** > * wakeup_source_prepare - Prepare a new wakeup source for initialization. > * @ws: Wakeup source to prepare. > @@ -442,6 +442,7 @@ EXPORT_SYMBOL_GPL(pm_stay_awake); > */ > static void wakeup_source_deactivate(struct wakeup_source *ws) > { > + unsigned int cnt, inpr; > ktime_t duration; > ktime_t now; > > @@ -476,6 +477,10 @@ static void wakeup_source_deactivate(str > * couter of wakeup events in progress simultaneously. > */ > atomic_add(MAX_IN_PROGRESS, &combined_event_count); > + > + split_counters(&cnt, &inpr); > + if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) > + wake_up(&wakeup_count_wait_queue); > } > > /** > @@ -667,14 +672,19 @@ bool pm_wakeup_pending(void) > bool pm_get_wakeup_count(unsigned int *count) > { > unsigned int cnt, inpr; > + DEFINE_WAIT(wait); > > for (;;) { > + prepare_to_wait(&wakeup_count_wait_queue, &wait, > + TASK_INTERRUPTIBLE); > split_counters(&cnt, &inpr); > if (inpr == 0 || signal_pending(current)) > break; > pm_wakeup_update_hit_counts(); > - schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT)); > + > + schedule(); > } > + finish_wait(&wakeup_count_wait_queue, &wait); > > split_counters(&cnt, &inpr); > *count = cnt;
Acked-by: mark gross <markgross@thegnar.org>
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