Commit 64bdff69 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM: cpuidle/suspend: Add s2idle usage and time state attributes 



Add a new attribute group called "s2idle" under the sysfs directory
of each cpuidle state that supports the ->enter_s2idle callback
and put two new attributes, "usage" and "time", into that group to
represent the number of times the given state was requested for
suspend-to-idle and the total time spent in suspend-to-idle after
requesting that state, respectively.

That will allow diagnostic information related to suspend-to-idle
to be collected without enabling advanced debug features and
analyzing dmesg output.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 8919d779

Documentation/ABI/testing/sysfs-devices-system-cpu

+25 −0
Original line number Diff line number Diff line
@@ -198,6 +198,31 @@ Description: 
		time (in microseconds) this cpu should spend in this idle state

		to make the transition worth the effort.



What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/

Date:		March 2018

KernelVersion:	v4.17

Contact:	Linux power management list <linux-pm@vger.kernel.org>

Description:

		Idle state usage statistics related to suspend-to-idle.



		This attribute group is only present for states that can be

		used in suspend-to-idle with suspended timekeeping.



What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/time

Date:		March 2018

KernelVersion:	v4.17

Contact:	Linux power management list <linux-pm@vger.kernel.org>

Description:

		Total time spent by the CPU in suspend-to-idle (with scheduler

		tick suspended) after requesting this state.



What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/usage

Date:		March 2018

KernelVersion:	v4.17

Contact:	Linux power management list <linux-pm@vger.kernel.org>

Description:

		Total number of times this state has been requested by the CPU

		while entering suspend-to-idle.



What:		/sys/devices/system/cpu/cpu#/cpufreq/*

Date:		pre-git history

drivers/cpuidle/cpuidle.c

+9 −0
Original line number Diff line number Diff line
@@ -131,6 +131,10 @@ int cpuidle_find_deepest_state(struct cpuidle_driver *drv, 
static void enter_s2idle_proper(struct cpuidle_driver *drv,

				struct cpuidle_device *dev, int index)

{

	ktime_t time_start, time_end;



	time_start = ns_to_ktime(local_clock());



	/*

	 * trace_suspend_resume() called by tick_freeze() for the last CPU

	 * executing it contains RCU usage regarded as invalid in the idle
@@ -152,6 +156,11 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, 
	 */

	RCU_NONIDLE(tick_unfreeze());

	start_critical_timings();



	time_end = ns_to_ktime(local_clock());



	dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start);

	dev->states_usage[index].s2idle_usage++;

}



/**

drivers/cpuidle/sysfs.c

+54 −0
Original line number Diff line number Diff line
@@ -330,6 +330,58 @@ struct cpuidle_state_kobj { 
	struct kobject kobj;

};



#ifdef CONFIG_SUSPEND

#define define_show_state_s2idle_ull_function(_name) \

static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \

					 struct cpuidle_state_usage *state_usage, \

					 char *buf)				\

{ \

	return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\

}



define_show_state_s2idle_ull_function(usage);

define_show_state_s2idle_ull_function(time);



#define define_one_state_s2idle_ro(_name, show) \

static struct cpuidle_state_attr attr_s2idle_##_name = \

	__ATTR(_name, 0444, show, NULL)



define_one_state_s2idle_ro(usage, show_state_s2idle_usage);

define_one_state_s2idle_ro(time, show_state_s2idle_time);



static struct attribute *cpuidle_state_s2idle_attrs[] = {

	&attr_s2idle_usage.attr,

	&attr_s2idle_time.attr,

	NULL

};



static const struct attribute_group cpuidle_state_s2idle_group = {

	.name	= "s2idle",

	.attrs	= cpuidle_state_s2idle_attrs,

};



static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)

{

	int ret;



	if (!kobj->state->enter_s2idle)

		return;



	ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);

	if (ret)

		pr_debug("%s: sysfs attribute group not created\n", __func__);

}



static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)

{

	if (kobj->state->enter_s2idle)

		sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);

}

#else

static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }

static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }

#endif /* CONFIG_SUSPEND */



#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)

#define kobj_to_state(k) (kobj_to_state_obj(k)->state)

#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
@@ -383,6 +435,7 @@ static struct kobj_type ktype_state_cpuidle = { 


static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)

{

	cpuidle_remove_s2idle_attr_group(device->kobjs[i]);

	kobject_put(&device->kobjs[i]->kobj);

	wait_for_completion(&device->kobjs[i]->kobj_unregister);

	kfree(device->kobjs[i]);
@@ -417,6 +470,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device) 
			kfree(kobj);

			goto error_state;

		}

		cpuidle_add_s2idle_attr_group(kobj);

		kobject_uevent(&kobj->kobj, KOBJ_ADD);

		device->kobjs[i] = kobj;

	}

include/linux/cpuidle.h

+4 −0
Original line number Diff line number Diff line
@@ -33,6 +33,10 @@ struct cpuidle_state_usage { 
	unsigned long long	disable;

	unsigned long long	usage;

	unsigned long long	time; /* in US */

#ifdef CONFIG_SUSPEND

	unsigned long long	s2idle_usage;

	unsigned long long	s2idle_time; /* in US */

#endif

};



struct cpuidle_state {

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