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From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Kalesh Singh <kaleshsingh@google.com>
Cc:     gregkh@linuxfoundation.org, trong@google.com, trong@android.com,
        sspatil@google.com, hridya@google.com, kernel-team@android.com,
        linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Subject: Re: [PATCH v2] PM/sleep: Expose suspend stats in sysfs
Date:   Mon, 26 Aug 2019 11:14:42 +0200
Message-ID: <2302681.QTKqPxHXBN@kreacher>
In-Reply-To: <20190731212933.23673-1-kaleshsingh@google.com>
References: <20190731050549.GA20809@kroah.com> <20190731212933.23673-1-kaleshsingh@google.com>
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On Wednesday, July 31, 2019 11:29:33 PM CEST Kalesh Singh wrote:
> Userspace can get suspend stats from the suspend stats debugfs node.
> Since debugfs doesn't have stable ABI, expose suspend stats in
> sysfs under /sys/power/suspend_stats.
> 
> Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
> ---
> Changes in v2:
>   - Added separate show functions for last_failed_* stats, as per Greg
>   - Updated ABI Documentation
> 
>  Documentation/ABI/testing/sysfs-power | 106 ++++++++++++++++++++++++++
>  kernel/power/main.c                   |  97 ++++++++++++++++++++++-
>  2 files changed, 201 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
> index 3c5130355011..6f87b9dd384b 100644
> --- a/Documentation/ABI/testing/sysfs-power
> +++ b/Documentation/ABI/testing/sysfs-power
> @@ -301,3 +301,109 @@ Description:
>  
>  		Using this sysfs file will override any values that were
>  		set using the kernel command line for disk offset.
> +
> +What:		/sys/power/suspend_stats
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats directory contains suspend related
> +		statistics.
> +
> +What:		/sys/power/suspend_stats/success
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/success file contains the number
> +		of times entering system sleep state succeeded.
> +
> +What:		/sys/power/suspend_stats/fail
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/fail file contains the number
> +		of times entering system sleep state failed.
> +
> +What:		/sys/power/suspend_stats/failed_freeze
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_freeze file contains the
> +		number of times freezing processes failed.
> +
> +What:		/sys/power/suspend_stats/failed_prepare
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_prepare file contains the
> +		number of times preparing all non-sysdev devices for
> +		a system PM transition failed.
> +
> +What:		/sys/power/suspend_stats/failed_resume
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_resume file contains the
> +		number of times executing "resume" callbacks of
> +		non-sysdev devices failed.
> +
> +What:		/sys/power/suspend_stats/failed_resume_early
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_resume_early file contains
> +		the number of times executing "early resume" callbacks
> +		of devices failed.
> +
> +What:		/sys/power/suspend_stats/failed_resume_noirq
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_resume_noirq file contains
> +		the number of times executing "noirq resume" callbacks
> +		of devices failed.
> +
> +What:		/sys/power/suspend_stats/failed_suspend
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_suspend file contains
> +		the number of times executing "suspend" callbacks
> +		of all non-sysdev devices failed.
> +
> +What:		/sys/power/suspend_stats/failed_suspend_late
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_suspend_late file contains
> +		the number of times executing "late suspend" callbacks
> +		of all devices failed.
> +
> +What:		/sys/power/suspend_stats/failed_suspend_noirq
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/failed_suspend_noirq file contains
> +		the number of times executing "noirq suspend" callbacks
> +		of all devices failed.
> +
> +What:		/sys/power/suspend_stats/last_failed_dev
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/last_failed_dev file contains
> +		the last device for which a suspend/resume callback failed.
> +
> +What:		/sys/power/suspend_stats/last_failed_errno
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/last_failed_errno file contains
> +		the errno of the last failed attempt at entering
> +		system sleep state.
> +
> +What:		/sys/power/suspend_stats/last_failed_step
> +Date:		July 2019
> +Contact:	Kalesh Singh <kaleshsingh96@gmail.com>
> +Description:
> +		The /sys/power/suspend_stats/last_failed_step file contains
> +		the last failed step in the suspend/resume path.
> diff --git a/kernel/power/main.c b/kernel/power/main.c
> index bdbd605c4215..938dc53a8b94 100644
> --- a/kernel/power/main.c
> +++ b/kernel/power/main.c
> @@ -254,7 +254,6 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
>  power_attr(pm_test);
>  #endif /* CONFIG_PM_SLEEP_DEBUG */
>  
> -#ifdef CONFIG_DEBUG_FS
>  static char *suspend_step_name(enum suspend_stat_step step)
>  {
>  	switch (step) {
> @@ -275,6 +274,92 @@ static char *suspend_step_name(enum suspend_stat_step step)
>  	}
>  }
>  
> +#define suspend_attr(_name)					\
> +static ssize_t _name##_show(struct kobject *kobj,		\
> +		struct kobj_attribute *attr, char *buf)		\
> +{								\
> +	return sprintf(buf, "%d\n", suspend_stats._name);	\
> +}								\
> +static struct kobj_attribute _name = __ATTR_RO(_name)
> +
> +suspend_attr(success);
> +suspend_attr(fail);
> +suspend_attr(failed_freeze);
> +suspend_attr(failed_prepare);
> +suspend_attr(failed_suspend);
> +suspend_attr(failed_suspend_late);
> +suspend_attr(failed_suspend_noirq);
> +suspend_attr(failed_resume);
> +suspend_attr(failed_resume_early);
> +suspend_attr(failed_resume_noirq);
> +
> +static ssize_t last_failed_dev_show(struct kobject *kobj,
> +		struct kobj_attribute *attr, char *buf)
> +{
> +	int index;
> +	char *last_failed_dev = NULL;
> +
> +	index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
> +	index %= REC_FAILED_NUM;
> +	last_failed_dev = suspend_stats.failed_devs[index];
> +
> +	return sprintf(buf, "%s\n", last_failed_dev);
> +}
> +static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
> +
> +static ssize_t last_failed_errno_show(struct kobject *kobj,
> +		struct kobj_attribute *attr, char *buf)
> +{
> +	int index;
> +	int last_failed_errno;
> +
> +	index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
> +	index %= REC_FAILED_NUM;
> +	last_failed_errno = suspend_stats.errno[index];
> +
> +	return sprintf(buf, "%d\n", last_failed_errno);
> +}
> +static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
> +
> +static ssize_t last_failed_step_show(struct kobject *kobj,
> +		struct kobj_attribute *attr, char *buf)
> +{
> +	int index;
> +	enum suspend_stat_step step;
> +	char *last_failed_step = NULL;
> +
> +	index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
> +	index %= REC_FAILED_NUM;
> +	step = suspend_stats.failed_steps[index];
> +	last_failed_step = suspend_step_name(step);
> +
> +	return sprintf(buf, "%s\n", last_failed_step);
> +}
> +static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
> +
> +static struct attribute *suspend_attrs[] = {
> +	&success.attr,
> +	&fail.attr,
> +	&failed_freeze.attr,
> +	&failed_prepare.attr,
> +	&failed_suspend.attr,
> +	&failed_suspend_late.attr,
> +	&failed_suspend_noirq.attr,
> +	&failed_resume.attr,
> +	&failed_resume_early.attr,
> +	&failed_resume_noirq.attr,
> +	&last_failed_dev.attr,
> +	&last_failed_errno.attr,
> +	&last_failed_step.attr,
> +	NULL,
> +};
> +
> +static struct attribute_group suspend_attr_group = {
> +	.name = "suspend_stats",
> +	.attrs = suspend_attrs,
> +};
> +
> +#ifdef CONFIG_DEBUG_FS
>  static int suspend_stats_show(struct seq_file *s, void *unused)
>  {
>  	int i, index, last_dev, last_errno, last_step;
> @@ -794,6 +879,14 @@ static const struct attribute_group attr_group = {
>  	.attrs = g,
>  };
>  
> +static const struct attribute_group *attr_groups[] = {
> +	&attr_group,
> +#ifdef CONFIG_PM_SLEEP
> +	&suspend_attr_group,
> +#endif
> +	NULL,
> +};
> +
>  struct workqueue_struct *pm_wq;
>  EXPORT_SYMBOL_GPL(pm_wq);
>  
> @@ -815,7 +908,7 @@ static int __init pm_init(void)
>  	power_kobj = kobject_create_and_add("power", NULL);
>  	if (!power_kobj)
>  		return -ENOMEM;
> -	error = sysfs_create_group(power_kobj, &attr_group);
> +	error = sysfs_create_groups(power_kobj, attr_groups);
>  	if (error)
>  		return error;
>  	pm_print_times_init();
> 

Applied with the Greg's R-by, thanks!