Re: [PATCH] power: new trace event to print device suspend and resumetime

From: Shuah Khan
Date: Tue Jul 16 2013 - 18:27:18 EST


On 07/16/2013 04:17 PM, Joe Perches wrote:
> 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?

oh yeah it does have s64.

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

ok.

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

Existing events in power.h use foo=val convention - I will make the
change to be consistent.

thanks for the review.
-- Shuah

Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research
America (Silicon Valley) shuah.kh@xxxxxxxxxxx | (970) 672-0658
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