[PATCH 2/2] PM / Sleep: User space wakeup sources garbage collector Kconfig option

Rafael J. Wysocki
2012-05-03T19:29:34Z

From: Rafael J. Wysocki <rjw@sisk.pl>

Make it possible to configure out the user space wakeup sources
garbage collector for debugging and default Android builds.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
kernel/power/Kconfig | 5 ++
kernel/power/wakelock.c | 101 +++++++++++++++++++++++++++++-------------------
2 files changed, 67 insertions(+), 39 deletions(-)

Index: linux/kernel/power/Kconfig
===================================================================
--- linux.orig/kernel/power/Kconfig
+++ linux/kernel/power/Kconfig
@@ -125,6 +125,11 @@ config PM_WAKELOCKS_LIMIT
default 100
depends on PM_WAKELOCKS

+config PM_WAKELOCKS_GC
+ bool "Garbage collector for user space wakeup sources"
+ depends on PM_WAKELOCKS
+ default y
+
config PM_RUNTIME
bool "Run-time PM core functionality"
depends on !IA64_HP_SIM
Index: linux/kernel/power/wakelock.c
===================================================================
--- linux.orig/kernel/power/wakelock.c
+++ linux/kernel/power/wakelock.c
@@ -17,21 +17,18 @@
#include <linux/rbtree.h>
#include <linux/slab.h>

-#define WL_GC_COUNT_MAX 100
-#define WL_GC_TIME_SEC 300
-
static DEFINE_MUTEX(wakelocks_lock);

struct wakelock {
char *name;
struct rb_node node;
struct wakeup_source ws;
+#ifdef CONFIG_PM_WAKELOCKS_GC
struct list_head lru;
+#endif
};

static struct rb_root wakelocks_tree = RB_ROOT;
-static LIST_HEAD(wakelocks_lru_list);
-static unsigned int wakelocks_gc_count;

ssize_t pm_show_wakelocks(char *buf, bool show_active)
{
@@ -79,6 +76,61 @@ static inline void increment_wakelocks_n
static inline void decrement_wakelocks_number(void) {}
#endif /* CONFIG_PM_WAKELOCKS_LIMIT */

+#ifdef CONFIG_PM_WAKELOCKS_GC
+#define WL_GC_COUNT_MAX 100
+#define WL_GC_TIME_SEC 300
+
+static LIST_HEAD(wakelocks_lru_list);
+static unsigned int wakelocks_gc_count;
+
+static inline void wakelocks_lru_add(struct wakelock *wl)
+{
+ list_add(&wl->lru, &wakelocks_lru_list);
+}
+
+static inline void wakelocks_lru_most_recent(struct wakelock *wl)
+{
+ list_move(&wl->lru, &wakelocks_lru_list);
+}
+
+static void wakelocks_gc(void)
+{
+ struct wakelock *wl, *aux;
+ ktime_t now;
+
+ if (++wakelocks_gc_count <= WL_GC_COUNT_MAX)
+ return;
+
+ now = ktime_get();
+ list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
+ u64 idle_time_ns;
+ bool active;
+
+ spin_lock_irq(&wl->ws.lock);
+ idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time));
+ active = wl->ws.active;
+ spin_unlock_irq(&wl->ws.lock);
+
+ if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
+ break;
+
+ if (!active) {
+ wakeup_source_remove(&wl->ws);
+ rb_erase(&wl->node, &wakelocks_tree);
+ list_del(&wl->lru);
+ kfree(wl->name);
+ kfree(wl);
+ decrement_wakelocks_number();
+ }
+ }
+ wakelocks_gc_count = 0;
+}
+#else /* !CONFIG_PM_WAKELOCKS_GC */
+static inline void wakelocks_lru_add(struct wakelock *wl) {}
+static inline void wakelocks_lru_most_recent(struct wakelock *wl) {}
+static inline void wakelocks_gc(void) {}
+#endif /* !CONFIG_PM_WAKELOCKS_GC */
+
static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
bool add_if_not_found)
{
@@ -123,7 +175,7 @@ static struct wakelock *wakelock_lookup_
wakeup_source_add(&wl->ws);
rb_link_node(&wl->node, parent, node);
rb_insert_color(&wl->node, &wakelocks_tree);
- list_add(&wl->lru, &wakelocks_lru_list);
+ wakelocks_lru_add(wl);
increment_wakelocks_number();
return wl;
}
@@ -166,42 +218,13 @@ int pm_wake_lock(const char *buf)
__pm_stay_awake(&wl->ws);
}

- list_move(&wl->lru, &wakelocks_lru_list);
+ wakelocks_lru_most_recent(wl);

out:
mutex_unlock(&wakelocks_lock);
return ret;
}

-static void wakelocks_gc(void)
-{
- struct wakelock *wl, *aux;
- ktime_t now = ktime_get();
-
- list_for_each_entry_safe_reverse(wl, aux, &wakelocks_lru_list, lru) {
- u64 idle_time_ns;
- bool active;
-
- spin_lock_irq(&wl->ws.lock);
- idle_time_ns = ktime_to_ns(ktime_sub(now, wl->ws.last_time));
- active = wl->ws.active;
- spin_unlock_irq(&wl->ws.lock);
-
- if (idle_time_ns < ((u64)WL_GC_TIME_SEC * NSEC_PER_SEC))
- break;
-
- if (!active) {
- wakeup_source_remove(&wl->ws);
- rb_erase(&wl->node, &wakelocks_tree);
- list_del(&wl->lru);
- kfree(wl->name);
- kfree(wl);
- decrement_wakelocks_number();
- }
- }
- wakelocks_gc_count = 0;
-}
-
int pm_wake_unlock(const char *buf)
{
struct wakelock *wl;
@@ -226,9 +249,9 @@ int pm_wake_unlock(const char *buf)
goto out;
}
__pm_relax(&wl->ws);
- list_move(&wl->lru, &wakelocks_lru_list);
- if (++wakelocks_gc_count > WL_GC_COUNT_MAX)
- wakelocks_gc();
+
+ wakelocks_lru_most_recent(wl);
+ wakelocks_gc();

out:
mutex_unlock(&wakelocks_lock);