On Wed, May 23, 2012 at 9:45 AM, Sameer Nanda <snanda@xxxxxxxxxxxx> wrote: > 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 <snanda@xxxxxxxxxxxx> > cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> > cc: Rafael J. Wysocki <rjw@xxxxxxx> > cc: Steven Rostedt <rostedt@xxxxxxxxxxx> > --- > Documentation/ABI/testing/sysfs-power | 13 ++++++++++++ > drivers/base/power/main.c | 4 +- > drivers/base/power/power.h | 11 ++++++++++ > kernel/power/main.c | 34 +++++++++++++++++++++++++++++++++ > 4 files changed, 60 insertions(+), 2 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power > index b464d12..79210d1 100644 > --- a/Documentation/ABI/testing/sysfs-power > +++ b/Documentation/ABI/testing/sysfs-power > @@ -172,3 +172,16 @@ Description: > > Reading from this file will display the current value, which is > set to 1 MB by default. > + > +What: /sys/power/pm_print_times > +Date: May 2012 > +Contact: Sameer Nanda <snanda@xxxxxxxxxxxx> > +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 b462c0e..ca8b2b5 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 eeb4bff..12c77b7 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 1c12581..97eea04 100644 > --- a/kernel/power/main.c > +++ b/kernel/power/main.c > @@ -132,6 +132,39 @@ 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 > @@ -411,6 +444,7 @@ static struct attribute * g[] = { > &wakeup_count_attr.attr, > #ifdef CONFIG_PM_DEBUG > &pm_test_attr.attr, > + &pm_print_times_attr.attr, > #endif > #endif > NULL, > -- > 1.7.7.3 > Greg KH, Rafael: any feedback on this patch? Questions I can help answer to help push this along? -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html