On Thu, Jan 04, 2018 at 12:32:04PM +0530, Viresh Kumar wrote: > This implements the debugfs interface for thermal cooling devices and > exposes some pretty useful statistics. These statistics have proven to > be quite useful specially while doing benchmarks related to the task > scheduler, where we want to make sure that nothing has disrupted the > test, specially the cooling device which may have put constraints on the > CPUs. The information exposed here tells us to what extent the CPUs were > constrained by the thermal framework. > > The read-only "transitions" file is per cooling device and it shows the > total number of cooling state transitions the device has gone through > since the time the cooling device is registered or the time when > statistics were reset last. > > The read-only "time_in_state/stateN" file is per cooling state and it > shows the time spent by the device in the respective cooling state. > > The write-only "reset" file is used to reset the statistics. > > This is how the directory structure looks like for a single cooling > device: > > $ ls -R /sys/kernel/debug/thermal/ > /sys/kernel/debug/thermal/: > cooling_device0 > > /sys/kernel/debug/thermal/cooling_device0: > reset time_in_state_ms transitions > > /sys/kernel/debug/thermal/cooling_device0/time_in_state_ms: > state0 state1 state2 state3
I would prefer this to go into sysfs. Reason is mainly because such stats are also useful on production systems, specially for collecting how a policy / deployment behaves across production population. Cheers, > > This is tested on ARM 32-bit Hisilicon hikey620 board running Ubuntu and > ARM 64-bit Hisilicon hikey960 board running Android. > > Signed-off-by: Viresh Kumar <[email protected]> > --- > drivers/thermal/Makefile | 1 + > drivers/thermal/thermal_core.c | 6 ++ > drivers/thermal/thermal_core.h | 18 ++++ > drivers/thermal/thermal_debugfs.c | 167 > ++++++++++++++++++++++++++++++++++++++ > drivers/thermal/thermal_helpers.c | 5 +- > drivers/thermal/thermal_sysfs.c | 1 + > include/linux/thermal.h | 1 + > 7 files changed, 198 insertions(+), 1 deletion(-) > create mode 100644 drivers/thermal/thermal_debugfs.c > > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 610344eb3e03..629f74e73871 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -6,6 +6,7 @@ > obj-$(CONFIG_THERMAL) += thermal_sys.o > thermal_sys-y += thermal_core.o thermal_sysfs.o \ > thermal_helpers.o > +obj-$(CONFIG_DEBUG_FS) += thermal_debugfs.o > > # interface to/from other layers providing sensors > thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 2b1b0ba393a4..bcc34648580f 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -997,6 +997,8 @@ __thermal_cooling_device_register(struct device_node *np, > THERMAL_EVENT_UNSPECIFIED); > mutex_unlock(&thermal_list_lock); > > + thermal_cooling_device_setup_debugfs(cdev); > + > return cdev; > } > > @@ -1104,6 +1106,7 @@ void thermal_cooling_device_unregister(struct > thermal_cooling_device *cdev) > > mutex_unlock(&thermal_list_lock); > > + thermal_cooling_device_remove_debugfs(cdev); > ida_simple_remove(&thermal_cdev_ida, cdev->id); > device_unregister(&cdev->device); > } > @@ -1544,6 +1547,8 @@ static int __init thermal_init(void) > pr_warn("Thermal: Can not register suspend notifier, return > %d\n", > result); > > + thermal_debugfs_register(); > + > return 0; > > exit_netlink: > @@ -1563,6 +1568,7 @@ static int __init thermal_init(void) > > static void __exit thermal_exit(void) > { > + thermal_debugfs_unregister(); > unregister_pm_notifier(&thermal_pm_nb); > of_thermal_destroy_zones(); > genetlink_exit(); > diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h > index 27e3b1df7360..3a8d50aa32dc 100644 > --- a/drivers/thermal/thermal_core.h > +++ b/drivers/thermal/thermal_core.h > @@ -151,4 +151,22 @@ of_thermal_get_trip_points(struct thermal_zone_device > *tz) > } > #endif > > +#ifdef CONFIG_DEBUG_FS > +void thermal_debugfs_register(void); > +void thermal_debugfs_unregister(void); > +void thermal_cooling_device_setup_debugfs(struct thermal_cooling_device > *cdev); > +void thermal_cooling_device_remove_debugfs(struct thermal_cooling_device > *cdev); > +void thermal_cooling_device_debugfs_update(struct thermal_cooling_device > *cdev, > + unsigned long new_state); > +#else > +static inline void thermal_debugfs_register(void) {} > +static inline void thermal_debugfs_unregister(void) {} > +static inline void > +thermal_cooling_device_setup_debugfs(struct thermal_cooling_device *cdev) {} > +static inline void > +thermal_cooling_device_remove_debugfs(struct thermal_cooling_device *cdev) {} > +static inline void > +thermal_cooling_device_debugfs_update(struct thermal_cooling_device *cdev, > + unsigned long new_state) {} > +#endif /* debugfs */ > #endif /* __THERMAL_CORE_H__ */ > diff --git a/drivers/thermal/thermal_debugfs.c > b/drivers/thermal/thermal_debugfs.c > new file mode 100644 > index 000000000000..077684197250 > --- /dev/null > +++ b/drivers/thermal/thermal_debugfs.c > @@ -0,0 +1,167 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Manages debugfs interface for thermal devices. > + * > + * Copyright (C) 2018 Linaro. > + * Viresh Kumar <[email protected]> > + */ > + > +#include <linux/device.h> > +#include <linux/debugfs.h> > +#include <linux/ktime.h> > +#include <linux/slab.h> > +#include <linux/spinlock.h> > + > +#include "thermal_core.h" > + > +struct cooling_time_in_state { > + ktime_t time; > + struct cooling_dev_debugfs_data *data; > +}; > + > +struct cooling_dev_debugfs_data { > + struct dentry *dentry; > + unsigned int total_trans; > + unsigned long state; > + unsigned long max_states; > + ktime_t last_time; > + struct cooling_time_in_state *time_in_state; > +}; > + > +static struct dentry *rootdir; > +static DEFINE_SPINLOCK(lock); > + > +static void update_time_in_state(struct cooling_dev_debugfs_data *data) > +{ > + ktime_t now = ktime_get(), delta; > + > + delta = ktime_sub(now, data->last_time); > + data->time_in_state[data->state].time = > + ktime_add(data->time_in_state[data->state].time, delta); > + data->last_time = now; > +} > + > +void thermal_cooling_device_debugfs_update(struct thermal_cooling_device > *cdev, > + unsigned long new_state) > +{ > + struct cooling_dev_debugfs_data *data = cdev->debugfs; > + > + if (!data) > + return; > + > + spin_lock(&lock); > + update_time_in_state(data); > + data->state = new_state; > + data->total_trans++; > + spin_unlock(&lock); > +} > + > +static int read_time_in_state(void *ptr, u64 *val) > +{ > + struct cooling_time_in_state *time_in_state = ptr; > + > + spin_lock(&lock); > + update_time_in_state(time_in_state->data); > + *val = ktime_to_ms(time_in_state->time); > + spin_unlock(&lock); > + > + return 0; > +} > + > +DEFINE_DEBUGFS_ATTRIBUTE(time_in_state_fops, read_time_in_state, NULL, > "%llu\n"); > + > +static int reset_stats(void *ptr, u64 val) > +{ > + struct cooling_dev_debugfs_data *data = ptr; > + int i; > + > + spin_lock(&lock); > + > + data->total_trans = 0; > + data->last_time = ktime_get(); > + > + for (i = 0; i < data->max_states; i++) > + data->time_in_state[i].time = ktime_set(0, 0); > + > + spin_unlock(&lock); > + > + return 0; > +} > + > +DEFINE_DEBUGFS_ATTRIBUTE(reset_fops, NULL, reset_stats, "%llu\n"); > + > +void thermal_cooling_device_setup_debugfs(struct thermal_cooling_device > *cdev) > +{ > + struct cooling_dev_debugfs_data *data; > + struct dentry *dentry; > + unsigned long states; > + int ret, size, i; > + char name[NAME_MAX]; > + > + ret = cdev->ops->get_max_state(cdev, &states); > + if (ret) > + return; > + > + size = sizeof(*data); > + size += sizeof(*data->time_in_state) * states; > + > + data = kzalloc(size, GFP_KERNEL); > + if (!data) > + return; > + > + data->time_in_state = (struct cooling_time_in_state *)(data + 1); > + cdev->debugfs = data; > + data->last_time = ktime_get(); > + data->max_states = states; > + > + data->dentry = debugfs_create_dir(dev_name(&cdev->device), rootdir); > + if (!data->dentry) > + goto free_data; > + > + debugfs_create_file_unsafe("reset", 0666, data->dentry, data, > &reset_fops); > + debugfs_create_u32("transitions", 0444, data->dentry, > + &data->total_trans); > + > + dentry = debugfs_create_dir("time_in_state_ms", data->dentry); > + if (!dentry) > + goto free_data_dentry; > + > + for (i = 0; i < states; i++) { > + data->time_in_state[i].data = data; > + snprintf(name, NAME_MAX, "state%u", i); > + debugfs_create_file_unsafe(name, 0444, dentry, > + &data->time_in_state[i], > + &time_in_state_fops); > + } > + > + return; > + > +free_data_dentry: > + debugfs_remove_recursive(data->dentry); > +free_data: > + kfree(data); > + cdev->debugfs = NULL; > +} > + > +void thermal_cooling_device_remove_debugfs(struct thermal_cooling_device > *cdev) > +{ > + struct cooling_dev_debugfs_data *data = cdev->debugfs; > + > + if (!data) > + return; > + > + debugfs_remove_recursive(data->dentry); > + kfree(data); > + cdev->debugfs = NULL; > +} > + > +void thermal_debugfs_register(void) > +{ > + rootdir = debugfs_create_dir("thermal", NULL); > +} > + > +void thermal_debugfs_unregister(void) > +{ > + debugfs_remove_recursive(rootdir); > + rootdir = NULL; > +} > diff --git a/drivers/thermal/thermal_helpers.c > b/drivers/thermal/thermal_helpers.c > index 8cdf75adcce1..8cfb2f4e7ea3 100644 > --- a/drivers/thermal/thermal_helpers.c > +++ b/drivers/thermal/thermal_helpers.c > @@ -187,7 +187,10 @@ void thermal_cdev_update(struct thermal_cooling_device > *cdev) > if (instance->target > target) > target = instance->target; > } > - cdev->ops->set_cur_state(cdev, target); > + > + if (!cdev->ops->set_cur_state(cdev, target)) > + thermal_cooling_device_debugfs_update(cdev, target); > + > cdev->updated = true; > mutex_unlock(&cdev->lock); > trace_cdev_update(cdev, target); > diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c > index fb80c96d8f73..be997ce3f32d 100644 > --- a/drivers/thermal/thermal_sysfs.c > +++ b/drivers/thermal/thermal_sysfs.c > @@ -722,6 +722,7 @@ thermal_cooling_device_cur_state_store(struct device *dev, > result = cdev->ops->set_cur_state(cdev, state); > if (result) > return result; > + thermal_cooling_device_debugfs_update(cdev, state); > return count; > } > > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > index 8c5302374eaa..338d165cefef 100644 > --- a/include/linux/thermal.h > +++ b/include/linux/thermal.h > @@ -148,6 +148,7 @@ struct thermal_cooling_device { > struct device device; > struct device_node *np; > void *devdata; > + void *debugfs; > const struct thermal_cooling_device_ops *ops; > bool updated; /* true if the cooling device does not need update */ > struct mutex lock; /* protect thermal_instances list */ > -- > 2.15.0.194.g9af6a3dea062 >
