[PATCH v4] PM / wakeup: show wakeup sources stats in sysfs
From: Tri Vo
Date: Mon Jul 15 2019 - 17:44:06 EST
Userspace can use wakeup_sources debugfs node to plot history of suspend
blocking wakeup sources over device's boot cycle. This information can
then be used (1) for power-specific bug reporting and (2) towards
attributing battery consumption to specific processes over a period of
time.
However, debugfs doesn't have stable ABI. For this reason, create a
'struct device' to expose wakeup sources statistics in sysfs under
/sys/class/wakeup/<name>/.
Introduce CONFIG_PM_SLEEP_STATS that enables/disables showing wakeup
source statistics in sysfs.
Co-developed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tri Vo <trong@xxxxxxxxxxx>
Tested-by: Tri Vo <trong@xxxxxxxxxxx>
Tested-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-class-wakeup | 70 +++++++++
drivers/base/power/Makefile | 1 +
drivers/base/power/wakeup.c | 12 +-
drivers/base/power/wakeup_stats.c | 149 +++++++++++++++++++
include/linux/pm_wakeup.h | 19 +++
kernel/power/Kconfig | 10 ++
kernel/power/wakelock.c | 10 ++
7 files changed, 269 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-class-wakeup
create mode 100644 drivers/base/power/wakeup_stats.c
v2:
- Updated Documentation/ABI/, as per Greg.
- Removed locks in attribute functions, as per Greg.
- Lifetimes of struct wakelock and struck wakeup_source are now different due to
the latter embedding a refcounted kobject. Changed it so that struct wakelock
only has a pointer to struct wakeup_source, instead of embedding it.
- Added CONFIG_PM_SLEEP_STATS that enables/disables wakeup source statistics in
sysfs.
v3:
Changes by Greg:
- Reworked code to use 'struct device' instead of raw kobjects.
- Updated documentation file.
- Only link wakeup_stats.o when CONFIG_PM_SLEEP_STATS is enabled.
Changes by Tri:
- Reverted changes to kernel/power/wakelock.c. 'struct device' hides kobject
operations. So no need to handle lifetimes in wakelock.c
v4:
- Added 'Co-developed-by:' and 'Tested-by:' fields to commit message.
- Moved new documentation to a separate file
Documentation/ABI/testing/sysfs-class-wakeup, as per Greg.
- Fixed copyright header in drivers/base/power/wakeup_stats.c, as per Greg.
diff --git a/Documentation/ABI/testing/sysfs-class-wakeup b/Documentation/ABI/testing/sysfs-class-wakeup
new file mode 100644
index 000000000000..30fb23eb9112
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-wakeup
@@ -0,0 +1,70 @@
+What: /sys/class/wakeup/
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ The /sys/class/wakeup/ directory contains pointers to all
+ wakeup sources in the kernel at that moment in time.
+
+What: /sys/class/wakeup/.../active_count
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the number of times the wakeup source was
+ activated.
+
+What: /sys/class/wakeup/.../event_count
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the number of signaled wakeup events
+ associated with the wakeup source.
+
+What: /sys/class/wakeup/.../wakeup_count
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the number of times the wakeup source might
+ abort suspend.
+
+What: /sys/class/wakeup/.../expire_count
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the number of times the wakeup source's
+ timeout has expired.
+
+What: /sys/class/wakeup/.../active_time_ms
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the amount of time the wakeup source has
+ been continuously active, in milliseconds. If the wakeup
+ source is not active, this file contains '0'.
+
+What: /sys/class/wakeup/.../total_time_ms
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the total amount of time this wakeup source
+ has been active, in milliseconds.
+
+What: /sys/class/wakeup/.../max_time_ms
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the maximum amount of time this wakeup
+ source has been continuously active, in milliseconds.
+
+What: /sys/class/wakeup/.../last_change_ms
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ This file contains the monotonic clock time when the wakeup
+ source was touched last time, in milliseconds.
+
+What: /sys/class/wakeup/.../prevent_suspend_time_ms
+Date: June 2019
+Contact: Tri Vo <trong@xxxxxxxxxxx>
+Description:
+ The file contains the total amount of time this wakeup source
+ has been preventing autosleep, in milliseconds.
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile
index e1bb691cf8f1..1963f53d9982 100644
--- a/drivers/base/power/Makefile
+++ b/drivers/base/power/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o qos.o runtime.o wakeirq.o
obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o
+obj-$(CONFIG_PM_SLEEP_STATS) += wakeup_stats.o
obj-$(CONFIG_PM_TRACE_RTC) += trace.o
obj-$(CONFIG_PM_GENERIC_DOMAINS) += domain.o domain_governor.o
obj-$(CONFIG_HAVE_CLK) += clock_ops.o
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 5b2b6a05a4f3..fd48e78c06b9 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -205,11 +205,18 @@ EXPORT_SYMBOL_GPL(wakeup_source_remove);
struct wakeup_source *wakeup_source_register(const char *name)
{
struct wakeup_source *ws;
+ int ret;
ws = wakeup_source_create(name);
- if (ws)
+ if (ws) {
+ ret = wakeup_source_sysfs_add(ws);
+ if (ret) {
+ kfree_const(ws->name);
+ kfree(ws);
+ return NULL;
+ }
wakeup_source_add(ws);
-
+ }
return ws;
}
EXPORT_SYMBOL_GPL(wakeup_source_register);
@@ -222,6 +229,7 @@ void wakeup_source_unregister(struct wakeup_source *ws)
{
if (ws) {
wakeup_source_remove(ws);
+ wakeup_source_sysfs_remove(ws);
wakeup_source_destroy(ws);
}
}
diff --git a/drivers/base/power/wakeup_stats.c b/drivers/base/power/wakeup_stats.c
new file mode 100644
index 000000000000..45e15856105b
--- /dev/null
+++ b/drivers/base/power/wakeup_stats.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wakeup statistics in sysfs
+ *
+ * Copyright (c) 2019 Linux Foundation
+ * Copyright (c) 2019 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
+ * Copyright (c) 2019 Google Inc.
+ */
+
+#include <linux/slab.h>
+#include <linux/kdev_t.h>
+
+#include "power.h"
+
+static struct class *wakeup_class;
+
+#define wakeup_attr(_name) \
+static ssize_t _name##_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ struct wakeup_source *ws = dev_get_drvdata(dev); \
+ \
+ return sprintf(buf, "%lu\n", ws->_name); \
+} \
+static DEVICE_ATTR_RO(_name)
+
+wakeup_attr(active_count);
+wakeup_attr(event_count);
+wakeup_attr(wakeup_count);
+wakeup_attr(expire_count);
+
+static ssize_t active_time_ms_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct wakeup_source *ws = dev_get_drvdata(dev);
+ ktime_t active_time =
+ ws->active ? ktime_sub(ktime_get(), ws->last_time) : 0;
+
+ return sprintf(buf, "%lld\n", ktime_to_ms(active_time));
+}
+static DEVICE_ATTR_RO(active_time_ms);
+
+static ssize_t total_time_ms_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct wakeup_source *ws = dev_get_drvdata(dev);
+ ktime_t active_time;
+ ktime_t total_time = ws->total_time;
+
+ if (ws->active) {
+ active_time = ktime_sub(ktime_get(), ws->last_time);
+ total_time = ktime_add(total_time, active_time);
+ }
+ return sprintf(buf, "%lld\n", ktime_to_ms(total_time));
+}
+static DEVICE_ATTR_RO(total_time_ms);
+
+static ssize_t max_time_ms_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct wakeup_source *ws = dev_get_drvdata(dev);
+ ktime_t active_time;
+ ktime_t max_time = ws->max_time;
+
+ if (ws->active) {
+ active_time = ktime_sub(ktime_get(), ws->last_time);
+ if (active_time > max_time)
+ max_time = active_time;
+ }
+ return sprintf(buf, "%lld\n", ktime_to_ms(max_time));
+}
+static DEVICE_ATTR_RO(max_time_ms);
+
+static ssize_t last_change_ms_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct wakeup_source *ws = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld\n", ktime_to_ms(ws->last_time));
+}
+static DEVICE_ATTR_RO(last_change_ms);
+
+static ssize_t prevent_suspend_time_ms_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct wakeup_source *ws = dev_get_drvdata(dev);
+ ktime_t prevent_sleep_time = ws->prevent_sleep_time;
+
+ if (ws->active && ws->autosleep_enabled) {
+ prevent_sleep_time = ktime_add(prevent_sleep_time,
+ ktime_sub(ktime_get(), ws->start_prevent_time));
+ }
+ return sprintf(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
+}
+static DEVICE_ATTR_RO(prevent_suspend_time_ms);
+
+static struct attribute *wakeup_source_attrs[] = {
+ &dev_attr_active_count.attr,
+ &dev_attr_event_count.attr,
+ &dev_attr_wakeup_count.attr,
+ &dev_attr_expire_count.attr,
+ &dev_attr_active_time_ms.attr,
+ &dev_attr_total_time_ms.attr,
+ &dev_attr_max_time_ms.attr,
+ &dev_attr_last_change_ms.attr,
+ &dev_attr_prevent_suspend_time_ms.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(wakeup_source);
+
+/**
+ * wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.
+ * @ws: Wakeup source to be added in sysfs.
+ */
+int wakeup_source_sysfs_add(struct wakeup_source *ws)
+{
+ struct device *dev;
+
+ dev = device_create_with_groups(wakeup_class, NULL, MKDEV(0, 0), ws,
+ wakeup_source_groups, "%s", ws->name);
+ if (IS_ERR(dev))
+ return PTR_ERR(dev);
+
+ ws->dev = dev;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wakeup_source_sysfs_add);
+
+/**
+ * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs.
+ * @ws: Wakeup source to be removed from sysfs.
+ */
+void wakeup_source_sysfs_remove(struct wakeup_source *ws)
+{
+ device_unregister(ws->dev);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_sysfs_remove);
+
+static int __init wakeup_sources_sysfs_init(void)
+{
+ wakeup_class = class_create(THIS_MODULE, "wakeup");
+ if (IS_ERR(wakeup_class))
+ return PTR_ERR(wakeup_class);
+
+ return 0;
+}
+
+postcore_initcall(wakeup_sources_sysfs_init);
diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
index ce57771fab9b..734141869c17 100644
--- a/include/linux/pm_wakeup.h
+++ b/include/linux/pm_wakeup.h
@@ -35,6 +35,7 @@ struct wake_irq;
* @relax_count: Number of times the wakeup source was deactivated.
* @expire_count: Number of times the wakeup source's timeout has expired.
* @wakeup_count: Number of times the wakeup source might abort suspend.
+ * @dev: Struct device for sysfs statistics about the wakeup source.
* @active: Status of the wakeup source.
* @has_timeout: The wakeup source has been activated with a timeout.
*/
@@ -55,6 +56,7 @@ struct wakeup_source {
unsigned long relax_count;
unsigned long expire_count;
unsigned long wakeup_count;
+ struct device *dev;
bool active:1;
bool autosleep_enabled:1;
};
@@ -181,6 +183,23 @@ static inline void pm_wakeup_dev_event(struct device *dev, unsigned int msec,
#endif /* !CONFIG_PM_SLEEP */
+#ifdef CONFIG_PM_SLEEP_STATS
+
+/* drivers/base/power/wakeup_stats.c */
+int wakeup_source_sysfs_add(struct wakeup_source *ws);
+void wakeup_source_sysfs_remove(struct wakeup_source *ws);
+
+#else /* !CONFIG_PM_SLEEP_STATS */
+
+static inline int wakeup_source_sysfs_add(struct wakeup_source *ws)
+{
+ return 0;
+}
+static inline void wakeup_source_sysfs_remove(struct wakeup_source *ws)
+{ }
+
+#endif /* !CONFIG_PM_SLEEP_STATS */
+
static inline void wakeup_source_init(struct wakeup_source *ws,
const char *name)
{
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index ff8592ddedee..604e1f087f14 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -195,6 +195,16 @@ config PM_SLEEP_DEBUG
def_bool y
depends on PM_DEBUG && PM_SLEEP
+config PM_SLEEP_STATS
+ bool "Wakeup sources statistics"
+ depends on PM_SLEEP
+ help
+ Expose wakeup sources statistics to user space via sysfs. Collected
+ statistics are located under /sys/power/wakeup_sources. For more
+ information, read <file:Documentation/ABI/testing/sysfs-class-wakeup>.
+
+ If in doubt, say N.
+
config DPM_WATCHDOG
bool "Device suspend/resume watchdog"
depends on PM_DEBUG && PSTORE && EXPERT
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
index 4210152e56f0..32726da3d6e6 100644
--- a/kernel/power/wakelock.c
+++ b/kernel/power/wakelock.c
@@ -122,6 +122,7 @@ static void __wakelocks_gc(struct work_struct *work)
if (!active) {
wakeup_source_remove(&wl->ws);
+ wakeup_source_sysfs_remove(&wl->ws);
rb_erase(&wl->node, &wakelocks_tree);
list_del(&wl->lru);
kfree(wl->name);
@@ -153,6 +154,7 @@ static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
struct rb_node **node = &wakelocks_tree.rb_node;
struct rb_node *parent = *node;
struct wakelock *wl;
+ int ret;
while (*node) {
int diff;
@@ -189,6 +191,14 @@ static struct wakelock *wakelock_lookup_add(const char *name, size_t len,
}
wl->ws.name = wl->name;
wl->ws.last_time = ktime_get();
+
+ ret = wakeup_source_sysfs_add(&wl->ws);
+ if (ret) {
+ kfree(wl->name);
+ kfree(wl);
+ return ERR_PTR(ret);
+ }
+
wakeup_source_add(&wl->ws);
rb_link_node(&wl->node, parent, node);
rb_insert_color(&wl->node, &wakelocks_tree);
--
2.22.0.510.g264f2c817a-goog