[RFC][PATCH 7/8] PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources

Rafael J. Wysocki
2012-04-22T21:21:41Z

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

Android uses one wakelock statistics that is only necessary for
opportunistic sleep. Namely, the prevent_suspend_time field
accumulates the total time the given wakelock has been locked
while "automatic suspend" was enabled. Add an analogous field,
prevent_sleep_time, to wakeup sources and make it behave in a similar
way.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
Documentation/ABI/testing/sysfs-devices-power | 11 ++++
drivers/base/power/sysfs.c | 24 ++++++++++
drivers/base/power/wakeup.c | 61 ++++++++++++++++++++++++--
include/linux/pm_wakeup.h | 4 +
include/linux/suspend.h | 1
kernel/power/autosleep.c | 6 ++
6 files changed, 102 insertions(+), 5 deletions(-)

Index: linux/include/linux/pm_wakeup.h
===================================================================
--- linux.orig/include/linux/pm_wakeup.h
+++ linux/include/linux/pm_wakeup.h
@@ -34,6 +34,7 @@
* @total_time: Total time this wakeup source has been active.
* @max_time: Maximum time this wakeup source has been continuously active.
* @last_time: Monotonic clock when the wakeup source's was touched last time.
+ * @prevent_sleep_time: Total time this source has been preventing autosleep.
* @event_count: Number of signaled wakeup events.
* @active_count: Number of times the wakeup sorce was activated.
* @relax_count: Number of times the wakeup sorce was deactivated.
@@ -51,12 +52,15 @@ struct wakeup_source {
ktime_t total_time;
ktime_t max_time;
ktime_t last_time;
+ ktime_t start_prevent_time;
+ ktime_t prevent_sleep_time;
unsigned long event_count;
unsigned long active_count;
unsigned long relax_count;
unsigned long expire_count;
unsigned long wakeup_count;
bool active:1;
+ bool autosleep_enabled:1;
};

#ifdef CONFIG_PM_SLEEP
Index: linux/drivers/base/power/wakeup.c
===================================================================
--- linux.orig/drivers/base/power/wakeup.c
+++ linux/drivers/base/power/wakeup.c
@@ -380,6 +380,8 @@ static void wakeup_source_activate(struc
ws->active = true;
ws->active_count++;
ws->last_time = ktime_get();
+ if (ws->autosleep_enabled)
+ ws->start_prevent_time = ws->last_time;

/* Increment the counter of events in progress. */
cec = atomic_inc_return(&combined_event_count);
@@ -449,6 +451,17 @@ void pm_stay_awake(struct device *dev)
}
EXPORT_SYMBOL_GPL(pm_stay_awake);

+#ifdef CONFIG_PM_AUTOSLEEP
+static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
+{
+ ktime_t delta = ktime_sub(now, ws->start_prevent_time);
+ ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
+}
+#else
+static inline void update_prevent_sleep_time(struct wakeup_source *ws,
+ ktime_t now) {}
+#endif
+
/**
* wakup_source_deactivate - Mark given wakeup source as inactive.
* @ws: Wakeup source to handle.
@@ -490,6 +503,9 @@ static void wakeup_source_deactivate(str
del_timer(&ws->timer);
ws->timer_expires = 0;

+ if (ws->autosleep_enabled)
+ update_prevent_sleep_time(ws, now);
+
/*
* Increment the counter of registered wakeup events and decrement the
* couter of wakeup events in progress simultaneously.
@@ -720,6 +736,34 @@ bool pm_save_wakeup_count(unsigned int c
return events_check_enabled;
}

+#ifdef CONFIG_PM_AUTOSLEEP
+/**
+ * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
+ * @enabled: Whether to set or to clear the autosleep_enabled flags.
+ */
+void pm_wakep_autosleep_enabled(bool set)
+{
+ struct wakeup_source *ws;
+ ktime_t now = ktime_get();
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
+ spin_lock_irq(&ws->lock);
+ if (ws->autosleep_enabled != set) {
+ ws->autosleep_enabled = set;
+ if (ws->active) {
+ if (set)
+ ws->start_prevent_time = now;
+ else
+ update_prevent_sleep_time(ws, now);
+ }
+ }
+ spin_unlock_irq(&ws->lock);
+ }
+ rcu_read_unlock();
+}
+#endif /* CONFIG_PM_AUTOSLEEP */
+
static struct dentry *wakeup_sources_stats_dentry;

/**
@@ -735,28 +779,37 @@ static int print_wakeup_source_stats(str
ktime_t max_time;
unsigned long active_count;
ktime_t active_time;
+ ktime_t prevent_sleep_time;
int ret;

spin_lock_irqsave(&ws->lock, flags);

total_time = ws->total_time;
max_time = ws->max_time;
+ prevent_sleep_time = ws->prevent_sleep_time;
active_count = ws->active_count;
if (ws->active) {
- active_time = ktime_sub(ktime_get(), ws->last_time);
+ ktime_t now = ktime_get();
+
+ active_time = ktime_sub(now, ws->last_time);
total_time = ktime_add(total_time, active_time);
if (active_time.tv64 > max_time.tv64)
max_time = active_time;
+
+ if (ws->autosleep_enabled)
+ prevent_sleep_time = ktime_add(prevent_sleep_time,
+ ktime_sub(now, ws->start_prevent_time));
} else {
active_time = ktime_set(0, 0);
}

ret = seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t"
- "%lld\t\t%lld\t\t%lld\t\t%lld\n",
+ "%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n",
ws->name, active_count, ws->event_count,
ws->wakeup_count, ws->expire_count,
ktime_to_ms(active_time), ktime_to_ms(total_time),
- ktime_to_ms(max_time), ktime_to_ms(ws->last_time));
+ ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
+ ktime_to_ms(prevent_sleep_time));

spin_unlock_irqrestore(&ws->lock, flags);

@@ -773,7 +826,7 @@ static int wakeup_sources_stats_show(str

seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
"expire_count\tactive_since\ttotal_time\tmax_time\t"
- "last_change\n");
+ "last_change\tprevent_suspend_time\n");

rcu_read_lock();
list_for_each_entry_rcu(ws, &wakeup_sources, entry)
Index: linux/include/linux/suspend.h
===================================================================
--- linux.orig/include/linux/suspend.h
+++ linux/include/linux/suspend.h
@@ -358,6 +358,7 @@ extern bool events_check_enabled;
extern bool pm_wakeup_pending(void);
extern bool pm_get_wakeup_count(unsigned int *count, bool block);
extern bool pm_save_wakeup_count(unsigned int count);
+extern void pm_wakep_autosleep_enabled(bool set);

static inline void lock_system_sleep(void)
{
Index: linux/drivers/base/power/sysfs.c
===================================================================
--- linux.orig/drivers/base/power/sysfs.c
+++ linux/drivers/base/power/sysfs.c
@@ -417,6 +417,27 @@ static ssize_t wakeup_last_time_show(str
}

static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
+
+#ifdef CONFIG_PM_AUTOSLEEP
+static ssize_t wakeup_prevent_sleep_time_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ s64 msec = 0;
+ bool enabled = false;
+
+ spin_lock_irq(&dev->power.lock);
+ if (dev->power.wakeup) {
+ msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
+ enabled = true;
+ }
+ spin_unlock_irq(&dev->power.lock);
+ return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_prevent_sleep_time_ms, 0444,
+ wakeup_prevent_sleep_time_show, NULL);
+#endif /* CONFIG_PM_AUTOSLEEP */
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM_ADVANCED_DEBUG
@@ -511,6 +532,9 @@ static struct attribute *wakeup_attrs[]
&dev_attr_wakeup_total_time_ms.attr,
&dev_attr_wakeup_max_time_ms.attr,
&dev_attr_wakeup_last_time_ms.attr,
+#ifdef CONFIG_PM_AUTOSLEEP
+ &dev_attr_wakeup_prevent_sleep_time_ms.attr,
+#endif
#endif
NULL,
};
Index: linux/Documentation/ABI/testing/sysfs-devices-power
===================================================================
--- linux.orig/Documentation/ABI/testing/sysfs-devices-power
+++ linux/Documentation/ABI/testing/sysfs-devices-power
@@ -158,6 +158,17 @@ Description:
not enabled to wake up the system from sleep states, this
attribute is not present.

+What: /sys/devices/.../power/wakeup_prevent_sleep_time_ms
+Date: February 2012
+Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+ The /sys/devices/.../wakeup_prevent_sleep_time_ms attribute
+ contains the total time the device has been preventing
+ opportunistic transitions to sleep states from occuring.
+ This attribute is read-only. If the device is not enabled to
+ wake up the system from sleep states, this attribute is not
+ present.
+
What: /sys/devices/.../power/autosuspend_delay_ms
Date: September 2010
Contact: Alan Stern <stern@rowland.harvard.edu>
Index: linux/kernel/power/autosleep.c
===================================================================
--- linux.orig/kernel/power/autosleep.c
+++ linux/kernel/power/autosleep.c
@@ -91,8 +91,12 @@ int pm_autosleep_set_state(suspend_state

__pm_relax(autosleep_ws);

- if (state > PM_SUSPEND_ON)
+ if (state > PM_SUSPEND_ON) {
+ pm_wakep_autosleep_enabled(true);
queue_up_suspend_work();
+ } else {
+ pm_wakep_autosleep_enabled(false);
+ }

mutex_unlock(&autosleep_lock);
return 0;