Re: [PATCH v2 4/4] ftrace: add latecy mesurement feature to workqueue tracer

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

> Index: b/include/trace/workqueue_event_types.h
> ===================================================================
> --- a/include/trace/workqueue_event_types.h	2009-04-13 13:58:21.000000000 +0900
> +++ b/include/trace/workqueue_event_types.h	2009-04-13 14:07:14.000000000 +0900
> @@ -43,6 +43,8 @@ TRACE_EVENT(workqueue_handler_entry,
>  		__field(pid_t,			thread_pid)
>  		__field(struct work_struct *,	work)
>  		__field(work_func_t,		func)
> +		__field(unsigned long,		expected_time)
> +		__field(unsigned long,		actual_time)
>  	),
>  
>  	TP_fast_assign(
> @@ -50,10 +52,14 @@ TRACE_EVENT(workqueue_handler_entry,
>  		__entry->thread_pid	= wq_thread->pid;
>  		__entry->work		= work;
>  		__entry->func		= work->func;
> +		__entry->expected_time	= work->expected_time;
> +		__entry->actual_time	= jiffies;
>  	),

Oops, that's my fault.
There is work->expected_time only if CONFIG_WORKQUEUE_TRACER is on.


>  
> -	TP_printk("thread=%s:%d func=%pF", __entry->thread_comm,
> -		__entry->thread_pid, __entry->func)
> +	TP_printk("thread=%s:%d latency=%lums func=%pF", __entry->thread_comm,
> +		  __entry->thread_pid,
> +		  jiffies_to_msecs(__entry->actual_time-__entry->expected_time),
> +		  __entry->func)
>  );