On Fri, May 18, 2012 at 11:37 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Fri, May 18, 2012 at 11:27:23AM -0700, Sameer Nanda wrote: >> Added event tracing for device_resume. This helps quickly pinpoint which >> devices take a long time to resume. >> >> Signed-off-by: Sameer Nanda <snanda@xxxxxxxxxxxx> >> --- >> Documentation/trace/events-power.txt | 20 +++++++++++ >> drivers/base/power/main.c | 10 ++++++ >> include/trace/events/power.h | 59 ++++++++++++++++++++++++++++++++++ >> 3 files changed, 89 insertions(+), 0 deletions(-) >> >> diff --git a/Documentation/trace/events-power.txt b/Documentation/trace/events-power.txt >> index cf794af..dbfb7f0 100644 >> --- a/Documentation/trace/events-power.txt >> +++ b/Documentation/trace/events-power.txt >> @@ -88,3 +88,23 @@ power_domain_target "%s state=%lu cpu_id=%lu" >> The first parameter gives the power domain name (e.g. "mpu_pwrdm"). >> The second parameter is the power domain target state. >> >> +4. Device resume events >> +======================= >> +The device resume events are used for measuring the time taken to resume >> +devices. >> + >> +device_resume_in "device=%s driver=%s" >> +device_resume_waited "device=%s driver=%s time_delta=%lld" >> +device_resume_out "device=%s driver=%s time_delta=%lld" >> + >> +The first parameter is the device that is being resumed. >> + >> +The second parameter is the driver associated with the device being resumed. >> + >> +The third parameter in device_resume_waited is the time delta from the entry >> +point of device_resume to the wait completion of parent device being resumed. >> +The unit for time_delta is us. >> + >> +The third parameter in device_resume_out is the time delta from the wait >> +completion of parent device being resumed to device_resume being completed. >> +The unit for time_delta is us. >> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c >> index b462c0e..3ed01cd 100644 >> --- a/drivers/base/power/main.c >> +++ b/drivers/base/power/main.c >> @@ -28,6 +28,7 @@ >> #include <linux/sched.h> >> #include <linux/async.h> >> #include <linux/suspend.h> >> +#include <trace/events/power.h> >> >> #include "../base.h" >> #include "power.h" >> @@ -565,11 +566,19 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) >> char *info = NULL; >> int error = 0; >> bool put = false; >> + s64 in_time = ktime_to_us(ktime_get()); >> + s64 wait_done_time; >> + >> + trace_device_resume_in(dev); >> >> TRACE_DEVICE(dev); >> TRACE_RESUME(0); > > Don't these TRACE_DEVICE() and TRACE_RESUME() calls already provide you > the same information you are wanting to determine above if you look at > the timestamps of the events? AFAICT, they are used for something completely different -- help solve suspend/resume issues by saving a hash in the RTC of the last device that suspended/resumed. They don't use the perf tracing mechanism at all. > Can you not do time processing in > userspace? Did you mean by using the TRACE_DEVICE/TRACE_RESUME functionality or something else? > > confused, > > greg k-h -- Sameer -- 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
