From 755113d7678681a137c330f7997ceb680adb644e Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Tue, 9 Jan 2024 10:41:11 +0100 Subject: thermal/debugfs: Add thermal cooling device debugfs information The thermal framework does not have any debug information except a sysfs stat which is a bit controversial. This one allocates big chunks of memory for every cooling devices with a high number of states and could represent on some systems in production several megabytes of memory for just a portion of it. As the sysfs is limited to a page size, the output is not exploitable with large data array and gets truncated. The patch provides the same information than sysfs except the transitions are dynamically allocated, thus they won't show more events than the ones which actually occurred. There is no longer a size limitation and it opens the field for more debugging information where the debugfs is designed for, not sysfs. The thermal debugfs directory structure tries to stay consistent with the sysfs one but in a very simplified way: thermal/ -- cooling_devices |-- 0 | |-- clear | |-- time_in_state_ms | |-- total_trans | `-- trans_table |-- 1 | |-- clear | |-- time_in_state_ms | |-- total_trans | `-- trans_table |-- 2 | |-- clear | |-- time_in_state_ms | |-- total_trans | `-- trans_table |-- 3 | |-- clear | |-- time_in_state_ms | |-- total_trans | `-- trans_table `-- 4 |-- clear |-- time_in_state_ms |-- total_trans `-- trans_table The content of the files in the cooling devices directory is the same as the sysfs one except for the trans_table which has the following format: Transition Hits 1->0 246 0->1 246 2->1 632 1->2 632 3->2 98 2->3 98 Signed-off-by: Daniel Lezcano [ rjw: White space fixups, rebase ] Signed-off-by: Rafael J. Wysocki --- include/linux/thermal.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 9d0427da32af..7defea8fa223 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -32,6 +32,7 @@ struct thermal_zone_device; struct thermal_cooling_device; struct thermal_instance; +struct thermal_debugfs; struct thermal_attr; enum thermal_trend { @@ -113,6 +114,9 @@ struct thermal_cooling_device { struct mutex lock; /* protect thermal_instances list */ struct list_head thermal_instances; struct list_head node; +#ifdef CONFIG_THERMAL_DEBUGFS + struct thermal_debugfs *debugfs; +#endif }; /** @@ -189,6 +193,9 @@ struct thermal_zone_device { struct list_head node; struct delayed_work poll_queue; enum thermal_notify_event notify_event; +#ifdef CONFIG_THERMAL_DEBUGFS + struct thermal_debugfs *debugfs; +#endif bool suspended; }; -- cgit v1.2.3 From 57a427c81c322c5f0cdfe7c46cdee553d18b1ec6 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Fri, 5 Jan 2024 14:45:11 +0100 Subject: thermal: core: Use kstrdup_const() during cooling device registration Some *thermal_cooling_device_register() calls pass a string literal as the 'type' parameter, so kstrdup_const() can be used instead of kstrdup() to avoid a memory allocation in such cases. Signed-off-by: Christophe JAILLET [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki --- drivers/thermal/thermal_core.c | 6 +++--- include/linux/thermal.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index abf4c2390b19..dfaa6341694a 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -845,7 +845,7 @@ static void thermal_release(struct device *dev) sizeof("cooling_device") - 1)) { cdev = to_cooling_device(dev); thermal_cooling_device_destroy_sysfs(cdev); - kfree(cdev->type); + kfree_const(cdev->type); ida_free(&thermal_cdev_ida, cdev->id); kfree(cdev); } @@ -917,7 +917,7 @@ __thermal_cooling_device_register(struct device_node *np, cdev->id = ret; id = ret; - cdev->type = kstrdup(type ? type : "", GFP_KERNEL); + cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL); if (!cdev->type) { ret = -ENOMEM; goto out_ida_remove; @@ -970,7 +970,7 @@ __thermal_cooling_device_register(struct device_node *np, out_cooling_dev: thermal_cooling_device_destroy_sysfs(cdev); out_cdev_type: - kfree(cdev->type); + kfree_const(cdev->type); out_ida_remove: ida_free(&thermal_cdev_ida, id); out_kfree_cdev: diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 7defea8fa223..3227335fb447 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -103,7 +103,7 @@ struct thermal_cooling_device_ops { struct thermal_cooling_device { int id; - char *type; + const char *type; unsigned long max_state; struct device device; struct device_node *np; -- cgit v1.2.3