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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2018-03-14 12:27:21 +01:00
parent 8919d779f1
commit 64bdff6980
4 changed files with 92 additions and 0 deletions

View File

@ -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

View File

@ -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++;
}
/**

View File

@ -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;
}

View File

@ -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 {