[v4] PM / wakeup: show wakeup sources stats in sysfs
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Message ID 20190715214348.81865-1-trong@android.com
State Not Applicable, archived
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  • [v4] PM / wakeup: show wakeup sources stats in sysfs
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Commit Message

Tri Vo July 15, 2019, 9:43 p.m. UTC
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@linuxfoundation.org>
Signed-off-by: Tri Vo <trong@android.com>
Tested-by: Tri Vo <trong@android.com>
Tested-by: Kalesh Singh <kaleshsingh@google.com>
---
 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.

--
2.22.0.510.g264f2c817a-goog

Comments

Rafael J. Wysocki July 15, 2019, 9:48 p.m. UTC | #1
On Mon, Jul 15, 2019 at 11:44 PM Tri Vo <trong@android.com> wrote:
>
> 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.

I'm not sure if this is really needed, but I'll let Greg decide.

Apart from this

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

>
> Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Tri Vo <trong@android.com>
> Tested-by: Tri Vo <trong@android.com>
> Tested-by: Kalesh Singh <kaleshsingh@google.com>
> ---
>  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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@android.com>
> +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@linuxfoundation.org>
> + * 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
>
Greg Kroah-Hartman July 16, 2019, 2:11 a.m. UTC | #2
On Mon, Jul 15, 2019 at 11:48:27PM +0200, Rafael J. Wysocki wrote:
> On Mon, Jul 15, 2019 at 11:44 PM Tri Vo <trong@android.com> wrote:
> >
> > 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.
> 
> I'm not sure if this is really needed, but I'll let Greg decide.

You are right.  Having zillions of config options is a pain, who is
going to turn this off?

But we can always remove the option before 5.4-rc1, so I'll take this
as-is for now :)

> Apart from this
> 
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thanks for the review!  I'll wait for 5.3-rc1 to come out before adding
this to my tree.

greg k-h
Tri Vo July 16, 2019, 4:16 a.m. UTC | #3
On Tue, Jul 16, 2019 at 11:13 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jul 15, 2019 at 11:48:27PM +0200, Rafael J. Wysocki wrote:
> > On Mon, Jul 15, 2019 at 11:44 PM Tri Vo <trong@android.com> wrote:
> > >
> > > 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.
> >
> > I'm not sure if this is really needed, but I'll let Greg decide.
>
> You are right.  Having zillions of config options is a pain, who is
> going to turn this off?
>
> But we can always remove the option before 5.4-rc1, so I'll take this
> as-is for now :)
>
> > Apart from this
> >
> > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> thanks for the review!  I'll wait for 5.3-rc1 to come out before adding
> this to my tree.

Greg, Rafael, thanks for taking the time to review this patch!
Rafael J. Wysocki July 16, 2019, 8:30 a.m. UTC | #4
On Tue, Jul 16, 2019 at 4:13 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jul 15, 2019 at 11:48:27PM +0200, Rafael J. Wysocki wrote:
> > On Mon, Jul 15, 2019 at 11:44 PM Tri Vo <trong@android.com> wrote:
> > >
> > > 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.
> >
> > I'm not sure if this is really needed, but I'll let Greg decide.
>
> You are right.  Having zillions of config options is a pain, who is
> going to turn this off?
>
> But we can always remove the option before 5.4-rc1, so I'll take this
> as-is for now :)
>
> > Apart from this
> >
> > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> thanks for the review!  I'll wait for 5.3-rc1 to come out before adding
> this to my tree.

So it occurred to me that maybe it's better if I apply it?  After all,
this is PM material. :-)

It is fine by me either way, but then I'm not sure if you want to get
future bug reports related to this if any ...
Greg Kroah-Hartman July 16, 2019, 8:39 a.m. UTC | #5
On Tue, Jul 16, 2019 at 10:30:48AM +0200, Rafael J. Wysocki wrote:
> On Tue, Jul 16, 2019 at 4:13 AM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Mon, Jul 15, 2019 at 11:48:27PM +0200, Rafael J. Wysocki wrote:
> > > On Mon, Jul 15, 2019 at 11:44 PM Tri Vo <trong@android.com> wrote:
> > > >
> > > > 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.
> > >
> > > I'm not sure if this is really needed, but I'll let Greg decide.
> >
> > You are right.  Having zillions of config options is a pain, who is
> > going to turn this off?
> >
> > But we can always remove the option before 5.4-rc1, so I'll take this
> > as-is for now :)
> >
> > > Apart from this
> > >
> > > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > thanks for the review!  I'll wait for 5.3-rc1 to come out before adding
> > this to my tree.
> 
> So it occurred to me that maybe it's better if I apply it?  After all,
> this is PM material. :-)

Heh, true, feel free to add:
	Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
to the patch then.

> It is fine by me either way, but then I'm not sure if you want to get
> future bug reports related to this if any ...

I get enough emails as it is, no need to ask for more :)

thanks,

greg k-h
Rafael J. Wysocki July 16, 2019, 9:36 a.m. UTC | #6
On Tue, Jul 16, 2019 at 10:39 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Jul 16, 2019 at 10:30:48AM +0200, Rafael J. Wysocki wrote:
> > On Tue, Jul 16, 2019 at 4:13 AM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > >
> > > On Mon, Jul 15, 2019 at 11:48:27PM +0200, Rafael J. Wysocki wrote:
> > > > On Mon, Jul 15, 2019 at 11:44 PM Tri Vo <trong@android.com> wrote:
> > > > >
> > > > > 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.
> > > >
> > > > I'm not sure if this is really needed, but I'll let Greg decide.
> > >
> > > You are right.  Having zillions of config options is a pain, who is
> > > going to turn this off?
> > >
> > > But we can always remove the option before 5.4-rc1, so I'll take this
> > > as-is for now :)
> > >
> > > > Apart from this
> > > >
> > > > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > >
> > > thanks for the review!  I'll wait for 5.3-rc1 to come out before adding
> > > this to my tree.
> >
> > So it occurred to me that maybe it's better if I apply it?  After all,
> > this is PM material. :-)
>
> Heh, true, feel free to add:
>         Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> to the patch then.

I will, thank you!

Patch
diff mbox series

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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@android.com>
+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@linuxfoundation.org>
+ * 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);