From 4b7760ba0dd3319f66886ab2335a0fbecdbc808a Mon Sep 17 00:00:00 2001 From: Sameer Nanda Date: Tue, 19 Jun 2012 22:23:33 +0200 Subject: [PATCH] PM / Sleep: add knob for printing device resume times Added a new knob called /sys/power/pm_print_times. Setting it to 1 enables printing of time taken by devices to suspend and resume. Setting it to 0 disables this printing (unless overridden by initcall_debug kernel command line option). Signed-off-by: Sameer Nanda Acked-by: Greg KH Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-power | 13 +++++++++++ drivers/base/power/main.c | 4 ++-- drivers/base/power/power.h | 11 +++++++++ kernel/power/main.c | 33 +++++++++++++++++++++++++++ 4 files changed, 59 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 31725ffeeb3..217772615d0 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -231,3 +231,16 @@ Description: Reads from this file return a string consisting of the names of wakeup sources created with the help of /sys/power/wake_lock that are inactive at the moment, separated with spaces. + +What: /sys/power/pm_print_times +Date: May 2012 +Contact: Sameer Nanda +Description: + The /sys/power/pm_print_times file allows user space to + control whether the time taken by devices to suspend and + resume is printed. These prints are useful for hunting down + devices that take too long to suspend or resume. + + Writing a "1" enables this printing while writing a "0" + disables it. The default value is "0". Reading from this file + will display the current value. diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 9cb845e4933..6e4db96958d 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -166,7 +166,7 @@ static ktime_t initcall_debug_start(struct device *dev) { ktime_t calltime = ktime_set(0, 0); - if (initcall_debug) { + if (pm_print_times) { pr_info("calling %s+ @ %i, parent: %s\n", dev_name(dev), task_pid_nr(current), dev->parent ? dev_name(dev->parent) : "none"); @@ -181,7 +181,7 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime, { ktime_t delta, rettime; - if (initcall_debug) { + if (pm_print_times) { rettime = ktime_get(); delta = ktime_sub(rettime, calltime); pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev), diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index eeb4bff9505..12c77b7ff8e 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -85,3 +85,14 @@ static inline int pm_qos_sysfs_add(struct device *dev) { return 0; } static inline void pm_qos_sysfs_remove(struct device *dev) {} #endif + +#ifdef CONFIG_PM_DEBUG + +extern int pm_print_times_enabled; +#define pm_print_times (initcall_debug || pm_print_times_enabled) + +#else /* CONFIG_PM_DEBUG */ + +#define pm_print_times initcall_debug + +#endif /* CONFIG_PM_DEBUG */ diff --git a/kernel/power/main.c b/kernel/power/main.c index 428f8a034e9..7beb3fb3670 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -132,6 +132,38 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr, } power_attr(pm_test); + +/* + * pm_print_times: print time taken by devices to suspend and resume. + * + * show() returns whether printing of suspend and resume times is enabled. + * store() accepts 0 or 1. 0 disables printing and 1 enables it. + */ +int pm_print_times_enabled; + +static ssize_t pm_print_times_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", pm_print_times_enabled); +} + +static ssize_t pm_print_times_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (kstrtoul(buf, 10, &val)) + return -EINVAL; + + if (val > 1) + return -EINVAL; + + pm_print_times_enabled = val; + return n; +} + +power_attr(pm_print_times); #endif /* CONFIG_PM_DEBUG */ #ifdef CONFIG_DEBUG_FS @@ -530,6 +562,7 @@ static struct attribute * g[] = { #endif #ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, + &pm_print_times_attr.attr, #endif #endif NULL,