Messages in this thread Patch in this message | | | From | "Masami Hiramatsu (Google)" <> | Subject | [PATCH v4.1] PM: sleep: Expose last succeeded resumed timestamp in sysfs | Date | Mon, 30 Oct 2023 18:53:32 +0900 |
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From: Masami Hiramatsu <mhiramat@kernel.org>
Expose last succeeded resumed timestamp as last_success_resume_time attribute of suspend_stats in sysfs.
There are some printk()s for printing the similar resume timing to dmesg, but those are recorded with local_clock(), and user can not compare it with current time. We also have tracing events but it requires CAP_SYS_ADMIN to use it.
This suspend_stats attribute is easy to access and only expose the timestamp in CLOCK_MONOTONIC. So user can find the actual resumed time and measure the elapsed time from the time when the kernel finished the resume to the user-space action (e.g. display the UI).
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> --- Changes in v4.1: - Fix document typo (again). Changes in v4: - Update description to add why. - Fix document typo. Changes in v3: - Add (unsigned long long) casting for %llu. - Add a line after last_success_resume_time_show(). Changes in v2: - Use %llu instead of %lu for printing u64 value. - Remove unneeded indent spaces from the last_success_resume_time line in the debugfs suspend_stat file. --- Documentation/ABI/testing/sysfs-power | 10 ++++++++++ include/linux/suspend.h | 2 ++ kernel/power/main.c | 15 +++++++++++++++ kernel/power/suspend.c | 1 + 4 files changed, 28 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index a3942b1036e2..e14975859766 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -442,6 +442,16 @@ Description: 'total_hw_sleep' and 'last_hw_sleep' may not be accurate. This number is measured in microseconds. +What: /sys/power/suspend_stats/last_success_resume_time +Date: Oct 2023 +Contact: Masami Hiramatsu <mhiramat@kernel.org> +Description: + The /sys/power/suspend_stats/last_success_resume_time file + contains the timestamp of when the kernel successfully + resumed from suspend/hibernate. + This floating point number is measured in seconds by monotonic + clock. + What: /sys/power/sync_on_suspend Date: October 2019 Contact: Jonas Meurer <jonas@freesources.org> diff --git a/include/linux/suspend.h b/include/linux/suspend.h index ef503088942d..ddd789044960 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -8,6 +8,7 @@ #include <linux/pm.h> #include <linux/mm.h> #include <linux/freezer.h> +#include <linux/timekeeping.h> #include <asm/errno.h> #ifdef CONFIG_VT @@ -71,6 +72,7 @@ struct suspend_stats { u64 last_hw_sleep; u64 total_hw_sleep; u64 max_hw_sleep; + struct timespec64 last_success_resume_time; enum suspend_stat_step failed_steps[REC_FAILED_NUM]; }; diff --git a/kernel/power/main.c b/kernel/power/main.c index f6425ae3e8b0..2ab23fd3daac 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -421,6 +421,17 @@ static ssize_t last_failed_step_show(struct kobject *kobj, } static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step); +static ssize_t last_success_resume_time_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%llu.%llu\n", + (unsigned long long)suspend_stats.last_success_resume_time.tv_sec, + (unsigned long long)suspend_stats.last_success_resume_time.tv_nsec); +} + +static struct kobj_attribute last_success_resume_time = + __ATTR_RO(last_success_resume_time); + static struct attribute *suspend_attrs[] = { &success.attr, &fail.attr, @@ -438,6 +449,7 @@ static struct attribute *suspend_attrs[] = { &last_hw_sleep.attr, &total_hw_sleep.attr, &max_hw_sleep.attr, + &last_success_resume_time.attr, NULL, }; @@ -514,6 +526,9 @@ static int suspend_stats_show(struct seq_file *s, void *unused) suspend_step_name( suspend_stats.failed_steps[index])); } + seq_printf(s, "last_success_resume_time:\t%-llu.%llu\n", + (unsigned long long)suspend_stats.last_success_resume_time.tv_sec, + (unsigned long long)suspend_stats.last_success_resume_time.tv_nsec); return 0; } diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index fa3bf161d13f..33334565d5a6 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -622,6 +622,7 @@ int pm_suspend(suspend_state_t state) dpm_save_failed_errno(error); } else { suspend_stats.success++; + ktime_get_ts64(&suspend_stats.last_success_resume_time); } pr_info("suspend exit\n"); return error;
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