From: Rafael J. Wysocki <[email protected]> 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 <[email protected]> --- Documentation/ABI/testing/sysfs-devices-system-cpu | 25 +++++++++ drivers/cpuidle/cpuidle.c | 9 +++ drivers/cpuidle/sysfs.c | 54 +++++++++++++++++++++ include/linux/cpuidle.h | 4 + 4 files changed, 92 insertions(+) Index: linux-pm/drivers/cpuidle/sysfs.c =================================================================== --- linux-pm.orig/drivers/cpuidle/sysfs.c +++ linux-pm/drivers/cpuidle/sysfs.c @@ -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_cpui 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(struc kfree(kobj); goto error_state; } + cpuidle_add_s2idle_attr_group(kobj); kobject_uevent(&kobj->kobj, KOBJ_ADD); device->kobjs[i] = kobj; } Index: linux-pm/include/linux/cpuidle.h =================================================================== --- linux-pm.orig/include/linux/cpuidle.h +++ linux-pm/include/linux/cpuidle.h @@ -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 { Index: linux-pm/drivers/cpuidle/cpuidle.c =================================================================== --- linux-pm.orig/drivers/cpuidle/cpuidle.c +++ linux-pm/drivers/cpuidle/cpuidle.c @@ -131,6 +131,10 @@ int cpuidle_find_deepest_state(struct cp 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 c */ 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++; } /** Index: linux-pm/Documentation/ABI/testing/sysfs-devices-system-cpu =================================================================== --- linux-pm.orig/Documentation/ABI/testing/sysfs-devices-system-cpu +++ linux-pm/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -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 <[email protected]> +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 <[email protected]> +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 <[email protected]> +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
