From 074037ec79bea73edf1b1ec72fef1010e83e3cc5 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 22 Sep 2010 22:09:10 +0200 Subject: 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 Acked-by: Greg Kroah-Hartman --- include/linux/suspend.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/suspend.h') diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 4af270ec2204..6b1712c51102 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -293,8 +293,8 @@ extern int unregister_pm_notifier(struct notifier_block *nb); extern bool events_check_enabled; extern bool pm_check_wakeup_events(void); -extern bool pm_get_wakeup_count(unsigned long *count); -extern bool pm_save_wakeup_count(unsigned long count); +extern bool pm_get_wakeup_count(unsigned int *count); +extern bool pm_save_wakeup_count(unsigned int count); #else /* !CONFIG_PM_SLEEP */ static inline int register_pm_notifier(struct notifier_block *nb) -- cgit v1.2.3 From dbeeec5fe868f2e2e92fe94daa2c5a047240fdc4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 4 Oct 2010 22:07:32 +0200 Subject: PM: Allow wakeup events to abort freezing of tasks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If there is a wakeup event during the freezing of tasks, suspend or hibernation will fail anyway. Since try_to_freeze_tasks() can take up to 20 seconds to complete or fail, aborting it as soon as a wakeup event is detected improves the worst case wakeup latency. Based on a patch from Arve Hjønnevåg. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek --- include/linux/suspend.h | 2 ++ kernel/power/process.c | 11 +++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'include/linux/suspend.h') diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 6b1712c51102..26697514c5ec 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -308,6 +308,8 @@ static inline int unregister_pm_notifier(struct notifier_block *nb) } #define pm_notifier(fn, pri) do { (void)(fn); } while (0) + +static inline bool pm_check_wakeup_events(void) { return true; } #endif /* !CONFIG_PM_SLEEP */ extern struct mutex pm_mutex; diff --git a/kernel/power/process.c b/kernel/power/process.c index 028a99598f49..e50b4c1b2a0f 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -40,6 +40,7 @@ static int try_to_freeze_tasks(bool sig_only) struct timeval start, end; u64 elapsed_csecs64; unsigned int elapsed_csecs; + bool wakeup = false; do_gettimeofday(&start); @@ -78,6 +79,11 @@ static int try_to_freeze_tasks(bool sig_only) if (!todo || time_after(jiffies, end_time)) break; + if (!pm_check_wakeup_events()) { + wakeup = true; + break; + } + /* * We need to retry, but first give the freezing tasks some * time to enter the regrigerator. @@ -97,8 +103,9 @@ static int try_to_freeze_tasks(bool sig_only) * but it cleans up leftover PF_FREEZE requests. */ printk("\n"); - printk(KERN_ERR "Freezing of tasks failed after %d.%02d seconds " + printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds " "(%d tasks refusing to freeze, wq_busy=%d):\n", + wakeup ? "aborted" : "failed", elapsed_csecs / 100, elapsed_csecs % 100, todo - wq_busy, wq_busy); @@ -107,7 +114,7 @@ static int try_to_freeze_tasks(bool sig_only) read_lock(&tasklist_lock); do_each_thread(g, p) { task_lock(p); - if (freezing(p) && !freezer_should_skip(p)) + if (!wakeup && freezing(p) && !freezer_should_skip(p)) sched_show_task(p); cancel_freezing(p); task_unlock(p); -- cgit v1.2.3