Re: [PATCH] power: new trace event to print device suspend andresume time

From: Joe Perches
Date: Tue Jul 16 2013 - 18:17:08 EST


On Tue, 2013-07-16 at 22:04 +0000, Shuah Khan wrote:
> On 07/16/2013 03:39 PM, Joe Perches wrote:
> > On Tue, 2013-07-16 at 15:23 -0600, Shuah Khan wrote:
> >> A new trace event is added to pm events to print time it takes to suspend and
> >> resume a device. It generates trace message that includes device, driver,
> >> parent information in addition to the type of pm ops invoked as well as the
> >> pm event and error status from the pm ops. Example trace below:
> >
> >> diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> > []
> >> @@ -66,6 +66,41 @@ TRACE_EVENT(machine_suspend,
> >> TP_printk("state=%lu", (unsigned long)__entry->state)
> >> );
> >>
> >> +TRACE_EVENT(device_pm_report_time,
> >> +
> >> + TP_PROTO(const char *device, const char *driver, const char *parent,
> >> + const char *pm_ops, ktime_t ops_time, char *pm_event_str,
> >> + int error),
> >> +
> >> + TP_ARGS(device, driver, parent, pm_ops, ops_time, pm_event_str, error),
> >> +
> >> + TP_STRUCT__entry(
> >> + __string(device, device)
> >> + __string(driver, driver)
> >> + __string(parent, parent)
> >> + __string(pm_ops, pm_ops)
> >> + __string(pm_event_str, pm_event_str)
> >> + __field(unsigned long long, ops_time)
> >
> > s64
>
> Followed the ktime_t example in include/trace/events/timer.h - thinking
> it would be the correct way to cast ktime_t :) I can change it to s64.

You mean this one below where s64 is used for the
variable type?

I do think the %llu is odd below here and it should be
%lld without the casts.

I prefer the TP_printk style of "foo=val" over "foo(val)"
but there's no requirement for one style over another.

c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 166) TP_STRUCT__entry(
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 167) __field( void *, hrtimer )
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 168) __field( void *, function )
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 169) __field( s64, expires )
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 170) __field( s64, softexpires )
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 171) ),
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 172)
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 173) TP_fast_assign(
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 174) __entry->hrtimer = hrtimer;
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 175) __entry->function = hrtimer->function;
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 176) __entry->expires = hrtimer_get_expires(hrtimer).tv64;
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 177) __entry->softexpires = hrtimer_get_softexpires(hrtimer).tv64;
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 178) ),
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 179)
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 180) TP_printk("hrtimer=%p function=%pf expires=%llu softexpires=%llu",
434a83c3f (Ingo Molnar 2009-10-15 11:50:39 +0200 181) __entry->hrtimer, __entry->function,
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 182) (unsigned long long)ktime_to_ns((ktime_t) {
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 183) .tv64 = __entry->expires }),
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 184) (unsigned long long)ktime_to_ns((ktime_t) {
c6a2a1770 (Xiao Guangrong 2009-08-10 10:51:23 +0800 185) .tv64 = __entry->softexpires }))


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