[PATCH 1/2] PM / Sleep: Make the limit of user space wakeup sources configurable

Rafael J. Wysocki
2012-05-03T19:29:50Z

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

Make it possible to configure out the check against the limit of
user space wakeup sources for debugging and default Android builds.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
kernel/power/Kconfig | 6 ++++++
kernel/power/wakelock.c | 31 ++++++++++++++++++++++++++-----
2 files changed, 32 insertions(+), 5 deletions(-)

Index: linux/kernel/power/Kconfig
===================================================================
--- linux.orig/kernel/power/Kconfig
+++ linux/kernel/power/Kconfig
@@ -119,6 +119,12 @@ config PM_WAKELOCKS
Allow user space to create, activate and deactivate wakeup source
objects with the help of a sysfs-based interface.

+config PM_WAKELOCKS_LIMIT
+ int "Maximum number of user space wakeup sources (0 = no limit)"
+ range 0 100000
+ default 100
+ depends on PM_WAKELOCKS
+
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
@@ -17,7 +17,6 @@
#include <linux/rbtree.h>
#include <linux/slab.h>

-#define WL_NUMBER_LIMIT 100
#define WL_GC_COUNT_MAX 100
#define WL_GC_TIME_SEC 300

@@ -32,7 +31,6 @@ struct wakelock {

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

ssize_t pm_show_wakelocks(char *buf, bool show_active)
@@ -58,6 +56,29 @@ ssize_t pm_show_wakelocks(char *buf, boo
return (str - buf);
}

+#if CONFIG_PM_WAKELOCKS_LIMIT > 0
+static unsigned int number_of_wakelocks;
+
+static inline bool wakelocks_limit_exceeded(void)
+{
+ return number_of_wakelocks > CONFIG_PM_WAKELOCKS_LIMIT;
+}
+
+static inline void increment_wakelocks_number(void)
+{
+ number_of_wakelocks++;
+}
+
+static inline void decrement_wakelocks_number(void)
+{
+ number_of_wakelocks--;
+}
+#else /* CONFIG_PM_WAKELOCKS_LIMIT = 0 */
+static inline bool wakelocks_limit_exceeded(void) { return false; }
+static inline void increment_wakelocks_number(void) {}
+static inline void decrement_wakelocks_number(void) {}
+#endif /* CONFIG_PM_WAKELOCKS_LIMIT */
+
static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
bool add_if_not_found)
{
@@ -85,7 +106,7 @@ static struct wakelock *wakelock_lookup_
if (!add_if_not_found)
return ERR_PTR(-EINVAL);

- if (number_of_wakelocks > WL_NUMBER_LIMIT)
+ if (wakelocks_limit_exceeded())
return ERR_PTR(-ENOSPC);

/* Not found, we have to add a new one. */
@@ -103,7 +124,7 @@ static struct wakelock *wakelock_lookup_
rb_link_node(&wl->node, parent, node);
rb_insert_color(&wl->node, &wakelocks_tree);
list_add(&wl->lru, &wakelocks_lru_list);
- number_of_wakelocks++;
+ increment_wakelocks_number();
return wl;
}

@@ -175,7 +196,7 @@ static void wakelocks_gc(void)
list_del(&wl->lru);
kfree(wl->name);
kfree(wl);
- number_of_wakelocks--;
+ decrement_wakelocks_number();
}
}
wakelocks_gc_count = 0;