[tip:perf/urgent] tracing: Fix timer tracing

[tip-bot for Arjan van de Ven <arjan@linux.intel.com>]

Commit-ID:  ede1b4290781ae82ccf0f2ecc6dada8d3dd35779
Gitweb:     http://git.kernel.org/tip/ede1b4290781ae82ccf0f2ecc6dada8d3dd35779
Author:     Arjan van de Ven <arjan@linux.intel.com>
AuthorDate: Wed, 18 Aug 2010 15:33:13 -0700
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 19 Aug 2010 13:00:41 +0200

tracing: Fix timer tracing

PowerTOP would like to be able to trace timers.

Unfortunately, the current timer tracing is not very useful: the
actual timer function is not recorded in the trace at the start
of timer execution.

Although this is recorded for timer "start" time (when it gets
armed), this is not useful; most timers get started early, and a
tracer like PowerTOP will never see this event, but will only
see the actual running of the  timer.

This patch just adds the function to the timer tracing; I've
verified with PowerTOP that now it can get useful information
about timers.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: xiaoguangrong@cn.fujitsu.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org> # .35.x, .34.x, .33.x
LKML-Reference: <4C6C5FA9.3000405@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 include/trace/events/timer.h |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
index c624126..425bcfe 100644
--- a/include/trace/events/timer.h
+++ b/include/trace/events/timer.h
@@ -81,14 +81,16 @@ TRACE_EVENT(timer_expire_entry,
 	TP_STRUCT__entry(
 		__field( void *,	timer	)
 		__field( unsigned long,	now	)
+		__field( void *,	function)
 	),
 
 	TP_fast_assign(
 		__entry->timer		= timer;
 		__entry->now		= jiffies;
+		__entry->function	= timer->function;
 	),
 
-	TP_printk("timer=%p now=%lu", __entry->timer, __entry->now)
+	TP_printk("timer=%p function=%pf now=%lu", __entry->timer, __entry->function,__entry->now)
 );
 
 /**
@@ -200,14 +202,16 @@ TRACE_EVENT(hrtimer_expire_entry,
 	TP_STRUCT__entry(
 		__field( void *,	hrtimer	)
 		__field( s64,		now	)
+		__field( void *,	function)
 	),
 
 	TP_fast_assign(
 		__entry->hrtimer	= hrtimer;
 		__entry->now		= now->tv64;
+		__entry->function	= hrtimer->function;
 	),
 
-	TP_printk("hrtimer=%p now=%llu", __entry->hrtimer,
+	TP_printk("hrtimer=%p function=%pf now=%llu", __entry->hrtimer, __entry->function,
 		  (unsigned long long)ktime_to_ns((ktime_t) { .tv64 = __entry->now }))
  );