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PM / autosleep: Use workqueue for user space wakeup sources garbage collector 

The synchronous synchronize_rcu() in wakeup_source_remove() makes
user process which writes to /sys/kernel/wake_unlock blocked sometimes.

For example, when android eventhub tries to release a wakelock, this
blocking process can occur, and eventhub can't get input events
for a while.

Using a work item instead of direct function call at pm_wake_unlock()
can prevent this unnecessary delay from happening.

Signed-off-by: SungEun Kim <cleaneye.kim@lge.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
SungEun Kim 2015-07-03 15:57:20 +09:00 committed by Rafael J. Wysocki
parent bc0195aad0
commit 6ce12a977b
1 changed files with 15 additions and 3 deletions
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18
kernel/power/wakelock.c
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@ -17,6 +17,7 @@
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include "power.h"
@ -83,7 +84,9 @@ static inline void decrement_wakelocks_number(void) {}
#define WL_GC_COUNT_MAX 100
#define WL_GC_TIME_SEC 300
static void __wakelocks_gc(struct work_struct *work);
static LIST_HEAD(wakelocks_lru_list);
static DECLARE_WORK(wakelock_work, __wakelocks_gc);
static unsigned int wakelocks_gc_count;
static inline void wakelocks_lru_add(struct wakelock *wl)
@ -96,13 +99,12 @@ static inline void wakelocks_lru_most_recent(struct wakelock *wl)
list_move(&wl->lru, &wakelocks_lru_list);
}
static void wakelocks_gc(void)
static void __wakelocks_gc(struct work_struct *work)
{
struct wakelock *wl, *aux;
ktime_t now;
if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
return;
mutex_lock(&wakelocks_lock);
now = ktime_get();
list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
@ -127,6 +129,16 @@ static void wakelocks_gc(void)
}
}
wakelocks_gc_count = 0;
mutex_unlock(&wakelocks_lock);
}
static void wakelocks_gc(void)
{
if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
return;
schedule_work(&wakelock_work);
}
#else /* !CONFIG_PM_WAKELOCKS_GC */
static inline void wakelocks_lru_add(struct wakelock *wl) {}