From f5f4eda4c9b9e26ec7d7c8ce083e386016ffc0f8 Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Fri, 5 Dec 2014 11:19:08 -0600 Subject: PM / QoS: Add debugfs support to view the list of constraints PM QoS requests are notoriously hard to debug and made even more so due to their highly dynamic nature. Having visibility into the internal data representation per constraint allows us to have much better appreciation of potential issues or bad usage by drivers in the system. So introduce for all classes of PM QoS, an entry in /sys/kernel/debug/pm_qos that shall show all the current requests as well as the snapshot of the value these requests boil down to. For example: ==> /sys/kernel/debug/pm_qos/cpu_dma_latency <== 1: 4444: Active 2: 2000000000: Default 3: 2000000000: Default 4: 2000000000: Default Type=Minimum, Value=4444, Requests: active=1 / total=4 ==> /sys/kernel/debug/pm_qos/memory_bandwidth <== Empty! ... The actual value listed will have their meaning based on the QoS it is on, the 'Type' indicates what logic it would use to collate the information - Minimum, Maximum, or Sum. Value is the collation of all requests. This interface also compares the values with the defaults for the QoS class and marks the ones that are currently active. Signed-off-by: Nishanth Menon Signed-off-by: Dave Gerlach Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- kernel/power/qos.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 89 insertions(+), 2 deletions(-) (limited to 'kernel/power') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 5f4c006c4b1e..97b0df71303e 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -41,6 +41,8 @@ #include #include #include +#include +#include #include #include @@ -182,6 +184,81 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) c->target_value = value; } +static inline int pm_qos_get_value(struct pm_qos_constraints *c); +static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused) +{ + struct pm_qos_object *qos = (struct pm_qos_object *)s->private; + struct pm_qos_constraints *c; + struct pm_qos_request *req; + char *type; + unsigned long flags; + int tot_reqs = 0; + int active_reqs = 0; + + if (IS_ERR_OR_NULL(qos)) { + pr_err("%s: bad qos param!\n", __func__); + return -EINVAL; + } + c = qos->constraints; + if (IS_ERR_OR_NULL(c)) { + pr_err("%s: Bad constraints on qos?\n", __func__); + return -EINVAL; + } + + /* Lock to ensure we have a snapshot */ + spin_lock_irqsave(&pm_qos_lock, flags); + if (plist_head_empty(&c->list)) { + seq_puts(s, "Empty!\n"); + goto out; + } + + switch (c->type) { + case PM_QOS_MIN: + type = "Minimum"; + break; + case PM_QOS_MAX: + type = "Maximum"; + break; + case PM_QOS_SUM: + type = "Sum"; + break; + default: + type = "Unknown"; + } + + plist_for_each_entry(req, &c->list, node) { + char *state = "Default"; + + if ((req->node).prio != c->default_value) { + active_reqs++; + state = "Active"; + } + tot_reqs++; + seq_printf(s, "%d: %d: %s\n", tot_reqs, + (req->node).prio, state); + } + + seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n", + type, pm_qos_get_value(c), active_reqs, tot_reqs); + +out: + spin_unlock_irqrestore(&pm_qos_lock, flags); + return 0; +} + +static int pm_qos_dbg_open(struct inode *inode, struct file *file) +{ + return single_open(file, pm_qos_dbg_show_requests, + inode->i_private); +} + +static const struct file_operations pm_qos_debug_fops = { + .open = pm_qos_dbg_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + /** * pm_qos_update_target - manages the constraints list and calls the notifiers * if needed @@ -509,12 +586,17 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); /* User space interface to PM QoS classes via misc devices */ -static int register_pm_qos_misc(struct pm_qos_object *qos) +static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d) { qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; qos->pm_qos_power_miscdev.name = qos->name; qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; + if (d) { + (void)debugfs_create_file(qos->name, S_IRUGO, d, + (void *)qos, &pm_qos_debug_fops); + } + return misc_register(&qos->pm_qos_power_miscdev); } @@ -608,11 +690,16 @@ static int __init pm_qos_power_init(void) { int ret = 0; int i; + struct dentry *d; BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); + d = debugfs_create_dir("pm_qos", NULL); + if (IS_ERR_OR_NULL(d)) + d = NULL; + for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { - ret = register_pm_qos_misc(pm_qos_array[i]); + ret = register_pm_qos_misc(pm_qos_array[i], d); if (ret < 0) { printk(KERN_ERR "pm_qos_param: %s setup failed\n", pm_qos_array[i]->name); -- cgit v1.2.3 From d78cb3680c8e95c100d5a351b8cfc7dd3c589b68 Mon Sep 17 00:00:00 2001 From: Rickard Strandqvist Date: Sun, 11 Jan 2015 23:27:38 +0100 Subject: PM / hibernate: Remove unused function Remove the function get_safe_write_buffer() that is not used anywhere. This was partially found by using a static code analysis program called cppcheck. Signed-off-by: Rickard Strandqvist Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/power') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 0c40c16174b4..8e75a5a1e9b4 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -2310,8 +2310,6 @@ static inline void free_highmem_data(void) free_image_page(buffer, PG_UNSAFE_CLEAR); } #else -static inline int get_safe_write_buffer(void) { return 0; } - static unsigned int count_highmem_image_pages(struct memory_bitmap *bm) { return 0; } -- cgit v1.2.3 From a64fc82c4f1598db024de7b3d79e7213379769ff Mon Sep 17 00:00:00 2001 From: Wonhong Kwon Date: Tue, 3 Feb 2015 17:22:00 +0900 Subject: PM / hibernate: exclude freed pages from allocated pages printout hibernate_preallocate_memory() prints out that how many pages are allocated, but it doesn't take into consideration the pages freed by free_unnecessary_pages(). Therefore, it always shows the count more than actually allocated. Signed-off-by: Wonhong Kwon [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'kernel/power') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 8e75a5a1e9b4..c24d5a23bf93 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1472,9 +1472,9 @@ static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, /** * free_unnecessary_pages - Release preallocated pages not needed for the image */ -static void free_unnecessary_pages(void) +static unsigned long free_unnecessary_pages(void) { - unsigned long save, to_free_normal, to_free_highmem; + unsigned long save, to_free_normal, to_free_highmem, free; save = count_data_pages(); if (alloc_normal >= save) { @@ -1495,6 +1495,7 @@ static void free_unnecessary_pages(void) else to_free_normal = 0; } + free = to_free_normal + to_free_highmem; memory_bm_position_reset(©_bm); @@ -1518,6 +1519,8 @@ static void free_unnecessary_pages(void) swsusp_unset_page_free(page); __free_page(page); } + + return free; } /** @@ -1707,7 +1710,7 @@ int hibernate_preallocate_memory(void) * pages in memory, but we have allocated more. Release the excessive * ones now. */ - free_unnecessary_pages(); + pages -= free_unnecessary_pages(); out: stop = ktime_get(); -- cgit v1.2.3