Re: [PATCH v1 04/12] PM: sleep: stats: Use an array of step failure counters

[Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>]

On Mon, Jan 22, 2024 at 12:27:21PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Instead of using a set of individual struct suspend_stats fields
> representing suspend step failure counters, use an array of counters
> indexed by enum suspend_stat_step for this purpose, which allows
> dpm_save_failed_step() to increment the appropriate counter
> automatically, so that its callers don't need to do that directly.
> 
> It also allows suspend_stats_show() to carry out a loop over the
> counters array to print their values.
> 
> Because the counters cannot become negative, use unsigned int for
> representing them.
> 
> The only user-observable impact of this change is a different
> ordering of entries in the suspend_stats debugfs file which is not
> expected to matter.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

> ---
>  drivers/base/power/main.c |   22 ++++++++-----------
>  include/linux/suspend.h   |   13 +++--------
>  kernel/power/main.c       |   51 ++++++++++++++++++++++++----------------------
>  kernel/power/suspend.c    |    1 
>  4 files changed, 40 insertions(+), 47 deletions(-)
> 
> Index: linux-pm/include/linux/suspend.h
> ===================================================================
> --- linux-pm.orig/include/linux/suspend.h
> +++ linux-pm/include/linux/suspend.h
> @@ -49,20 +49,14 @@ enum suspend_stat_step {
>  	SUSPEND_SUSPEND_NOIRQ,
>  	SUSPEND_RESUME_NOIRQ,
>  	SUSPEND_RESUME_EARLY,
> -	SUSPEND_RESUME
> +	SUSPEND_RESUME,
> +	SUSPEND_NR_STEPS
>  };
>  
>  struct suspend_stats {
> +	unsigned int step_failures[SUSPEND_NR_STEPS];
>  	int	success;
>  	int	fail;
> -	int	failed_freeze;
> -	int	failed_prepare;
> -	int	failed_suspend;
> -	int	failed_suspend_late;
> -	int	failed_suspend_noirq;
> -	int	failed_resume;
> -	int	failed_resume_early;
> -	int	failed_resume_noirq;
>  #define	REC_FAILED_NUM	2
>  	int	last_failed_dev;
>  	char	failed_devs[REC_FAILED_NUM][40];
> @@ -95,6 +89,7 @@ static inline void dpm_save_failed_errno
>  
>  static inline void dpm_save_failed_step(enum suspend_stat_step step)
>  {
> +	suspend_stats.step_failures[step]++;
>  	suspend_stats.failed_steps[suspend_stats.last_failed_step] = step;
>  	suspend_stats.last_failed_step++;
>  	suspend_stats.last_failed_step %= REC_FAILED_NUM;
> Index: linux-pm/kernel/power/main.c
> ===================================================================
> --- linux-pm.orig/kernel/power/main.c
> +++ linux-pm/kernel/power/main.c
> @@ -341,18 +341,28 @@ static struct kobj_attribute _name = __A
>  
>  suspend_attr(success, "%d\n");
>  suspend_attr(fail, "%d\n");
> -suspend_attr(failed_freeze, "%d\n");
> -suspend_attr(failed_prepare, "%d\n");
> -suspend_attr(failed_suspend, "%d\n");
> -suspend_attr(failed_suspend_late, "%d\n");
> -suspend_attr(failed_suspend_noirq, "%d\n");
> -suspend_attr(failed_resume, "%d\n");
> -suspend_attr(failed_resume_early, "%d\n");
> -suspend_attr(failed_resume_noirq, "%d\n");
>  suspend_attr(last_hw_sleep, "%llu\n");
>  suspend_attr(total_hw_sleep, "%llu\n");
>  suspend_attr(max_hw_sleep, "%llu\n");
>  
> +#define suspend_step_attr(_name, step)		\
> +static ssize_t _name##_show(struct kobject *kobj,		\
> +		struct kobj_attribute *attr, char *buf)		\
> +{								\
> +	return sprintf(buf, "%u\n",				\
> +		       suspend_stats.step_failures[step]);	\
> +}								\
> +static struct kobj_attribute _name = __ATTR_RO(_name)
> +
> +suspend_step_attr(failed_freeze, SUSPEND_FREEZE);
> +suspend_step_attr(failed_prepare, SUSPEND_PREPARE);
> +suspend_step_attr(failed_suspend, SUSPEND_SUSPEND);
> +suspend_step_attr(failed_suspend_late, SUSPEND_SUSPEND_LATE);
> +suspend_step_attr(failed_suspend_noirq, SUSPEND_SUSPEND_NOIRQ);
> +suspend_step_attr(failed_resume, SUSPEND_RESUME);
> +suspend_step_attr(failed_resume_early, SUSPEND_RESUME_EARLY);
> +suspend_step_attr(failed_resume_noirq, SUSPEND_RESUME_NOIRQ);
> +
>  static ssize_t last_failed_dev_show(struct kobject *kobj,
>  		struct kobj_attribute *attr, char *buf)
>  {
> @@ -439,6 +449,7 @@ static const struct attribute_group susp
>  static int suspend_stats_show(struct seq_file *s, void *unused)
>  {
>  	int i, index, last_dev, last_errno, last_step;
> +	enum suspend_stat_step step;
>  
>  	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
>  	last_dev %= REC_FAILED_NUM;
> @@ -446,22 +457,14 @@ static int suspend_stats_show(struct seq
>  	last_errno %= REC_FAILED_NUM;
>  	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
>  	last_step %= REC_FAILED_NUM;
> -	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
> -			"%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
> -			"success", suspend_stats.success,
> -			"fail", suspend_stats.fail,
> -			"failed_freeze", suspend_stats.failed_freeze,
> -			"failed_prepare", suspend_stats.failed_prepare,
> -			"failed_suspend", suspend_stats.failed_suspend,
> -			"failed_suspend_late",
> -				suspend_stats.failed_suspend_late,
> -			"failed_suspend_noirq",
> -				suspend_stats.failed_suspend_noirq,
> -			"failed_resume", suspend_stats.failed_resume,
> -			"failed_resume_early",
> -				suspend_stats.failed_resume_early,
> -			"failed_resume_noirq",
> -				suspend_stats.failed_resume_noirq);
> +
> +	seq_printf(s, "success: %d\nfail: %d\n",
> +		   suspend_stats.success, suspend_stats.fail);
> +
> +	for (step = SUSPEND_FREEZE; step < SUSPEND_NR_STEPS; step++)
> +		seq_printf(s, "failed_%s: %u\n", suspend_step_names[step],
> +			   suspend_stats.step_failures[step]);
> +
>  	seq_printf(s,	"failures:\n  last_failed_dev:\t%-s\n",
>  			suspend_stats.failed_devs[last_dev]);
>  	for (i = 1; i < REC_FAILED_NUM; i++) {
> Index: linux-pm/kernel/power/suspend.c
> ===================================================================
> --- linux-pm.orig/kernel/power/suspend.c
> +++ linux-pm/kernel/power/suspend.c
> @@ -367,7 +367,6 @@ static int suspend_prepare(suspend_state
>  	if (!error)
>  		return 0;
>  
> -	suspend_stats.failed_freeze++;
>  	dpm_save_failed_step(SUSPEND_FREEZE);
>  	pm_notifier_call_chain(PM_POST_SUSPEND);
>   Restore:
> Index: linux-pm/drivers/base/power/main.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/main.c
> +++ linux-pm/drivers/base/power/main.c
> @@ -686,7 +686,6 @@ Out:
>  	TRACE_RESUME(error);
>  
>  	if (error) {
> -		suspend_stats.failed_resume_noirq++;
>  		dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
>  		dpm_save_failed_dev(dev_name(dev));
>  		pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
> @@ -817,7 +816,6 @@ Out:
>  	complete_all(&dev->power.completion);
>  
>  	if (error) {
> -		suspend_stats.failed_resume_early++;
>  		dpm_save_failed_step(SUSPEND_RESUME_EARLY);
>  		dpm_save_failed_dev(dev_name(dev));
>  		pm_dev_err(dev, state, async ? " async early" : " early", error);
> @@ -974,7 +972,6 @@ static void device_resume(struct device
>  	TRACE_RESUME(error);
>  
>  	if (error) {
> -		suspend_stats.failed_resume++;
>  		dpm_save_failed_step(SUSPEND_RESUME);
>  		dpm_save_failed_dev(dev_name(dev));
>  		pm_dev_err(dev, state, async ? " async" : "", error);
> @@ -1323,10 +1320,9 @@ static int dpm_noirq_suspend_devices(pm_
>  	if (!error)
>  		error = async_error;
>  
> -	if (error) {
> -		suspend_stats.failed_suspend_noirq++;
> +	if (error)
>  		dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
> -	}
> +
>  	dpm_show_time(starttime, state, error, "noirq");
>  	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
>  	return error;
> @@ -1509,8 +1505,8 @@ int dpm_suspend_late(pm_message_t state)
>  	async_synchronize_full();
>  	if (!error)
>  		error = async_error;
> +
>  	if (error) {
> -		suspend_stats.failed_suspend_late++;
>  		dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
>  		dpm_resume_early(resume_event(state));
>  	}
> @@ -1789,10 +1785,10 @@ int dpm_suspend(pm_message_t state)
>  	async_synchronize_full();
>  	if (!error)
>  		error = async_error;
> -	if (error) {
> -		suspend_stats.failed_suspend++;
> +
> +	if (error)
>  		dpm_save_failed_step(SUSPEND_SUSPEND);
> -	}
> +
>  	dpm_show_time(starttime, state, error, NULL);
>  	trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
>  	return error;
> @@ -1943,11 +1939,11 @@ int dpm_suspend_start(pm_message_t state
>  	int error;
>  
>  	error = dpm_prepare(state);
> -	if (error) {
> -		suspend_stats.failed_prepare++;
> +	if (error)
>  		dpm_save_failed_step(SUSPEND_PREPARE);
> -	} else
> +	else
>  		error = dpm_suspend(state);
> +
>  	dpm_show_time(starttime, state, error, "start");
>  	return error;
>  }
> 
> 
> 
>