PM / Wakeup: Introduce wakeup source objects and event statistics (v3)
Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet). Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.
Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/kernel/power/main.c b/kernel/power/main.c
index f06ad6e..6b12a0cf 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -237,18 +237,18 @@
struct kobj_attribute *attr,
char *buf)
{
- unsigned long val;
+ unsigned int val;
- return pm_get_wakeup_count(&val) ? sprintf(buf, "%lu\n", val) : -EINTR;
+ return pm_get_wakeup_count(&val) ? sprintf(buf, "%u\n", val) : -EINTR;
}
static ssize_t wakeup_count_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
- unsigned long val;
+ unsigned int val;
- if (sscanf(buf, "%lu", &val) == 1) {
+ if (sscanf(buf, "%u", &val) == 1) {
if (pm_save_wakeup_count(val))
return n;
}