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authorMario Limonciello <mario.limonciello@amd.com>2023-04-17 17:27:05 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2023-04-20 19:06:12 +0200
commitb52124a78ab34eb0754e32edc0c9996937779176 (patch)
tree35050fa7febe8f3fb465d98280950c7171f9b194 /Documentation
parentLinux 6.3-rc7 (diff)
downloadlinux-b52124a78ab34eb0754e32edc0c9996937779176.tar.xz
linux-b52124a78ab34eb0754e32edc0c9996937779176.zip
PM: Add sysfs files to represent time spent in hardware sleep state
Userspace can't easily discover how much of a sleep cycle was spent in a hardware sleep state without using kernel tracing and vendor specific sysfs or debugfs files. To make this information more discoverable, introduce 3 new sysfs files: 1) The time spent in a hw sleep state for last cycle. 2) The time spent in a hw sleep state since the kernel booted 3) The maximum time that the hardware can report for a sleep cycle. All of these files will be present only if the system supports s2idle. Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-power29
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index f99d433ff311..a3942b1036e2 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -413,6 +413,35 @@ Description:
The /sys/power/suspend_stats/last_failed_step file contains
the last failed step in the suspend/resume path.
+What: /sys/power/suspend_stats/last_hw_sleep
+Date: June 2023
+Contact: Mario Limonciello <mario.limonciello@amd.com>
+Description:
+ The /sys/power/suspend_stats/last_hw_sleep file
+ contains the duration of time spent in a hardware sleep
+ state in the most recent system suspend-resume cycle.
+ This number is measured in microseconds.
+
+What: /sys/power/suspend_stats/total_hw_sleep
+Date: June 2023
+Contact: Mario Limonciello <mario.limonciello@amd.com>
+Description:
+ The /sys/power/suspend_stats/total_hw_sleep file
+ contains the aggregate of time spent in a hardware sleep
+ state since the kernel was booted. This number
+ is measured in microseconds.
+
+What: /sys/power/suspend_stats/max_hw_sleep
+Date: June 2023
+Contact: Mario Limonciello <mario.limonciello@amd.com>
+Description:
+ The /sys/power/suspend_stats/max_hw_sleep file
+ contains the maximum amount of time that the hardware can
+ report for time spent in a hardware sleep state. When sleep
+ cycles are longer than this time, the values for
+ 'total_hw_sleep' and 'last_hw_sleep' may not be accurate.
+ This number is measured in microseconds.
+
What: /sys/power/sync_on_suspend
Date: October 2019
Contact: Jonas Meurer <jonas@freesources.org>