From e5e25cf47b0bdd1f7e9b8bb6368ee48e16de0c87 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 18 Sep 2009 00:54:43 +0200
Subject: tracing: Factorize the events profile accounting

Factorize the events enabling accounting in a common tracing core
helper. This reduces the size of the profile_enable() and
profile_disable() callbacks for each trace events.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_event_profile.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

(limited to 'kernel/trace/trace_event_profile.c')

diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 55a25c933d1..df4a74efd50 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -8,6 +8,14 @@
 #include <linux/module.h>
 #include "trace.h"
 
+static int ftrace_profile_enable_event(struct ftrace_event_call *event)
+{
+	if (atomic_inc_return(&event->profile_count))
+		return 0;
+
+	return event->profile_enable();
+}
+
 int ftrace_profile_enable(int event_id)
 {
 	struct ftrace_event_call *event;
@@ -17,7 +25,7 @@ int ftrace_profile_enable(int event_id)
 	list_for_each_entry(event, &ftrace_events, list) {
 		if (event->id == event_id && event->profile_enable &&
 		    try_module_get(event->mod)) {
-			ret = event->profile_enable(event);
+			ret = ftrace_profile_enable_event(event);
 			break;
 		}
 	}
@@ -26,6 +34,14 @@ int ftrace_profile_enable(int event_id)
 	return ret;
 }
 
+static void ftrace_profile_disable_event(struct ftrace_event_call *event)
+{
+	if (!atomic_add_negative(-1, &event->profile_count))
+		return;
+
+	event->profile_disable();
+}
+
 void ftrace_profile_disable(int event_id)
 {
 	struct ftrace_event_call *event;
@@ -33,7 +49,7 @@ void ftrace_profile_disable(int event_id)
 	mutex_lock(&event_mutex);
 	list_for_each_entry(event, &ftrace_events, list) {
 		if (event->id == event_id) {
-			event->profile_disable(event);
+			ftrace_profile_disable_event(event);
 			module_put(event->mod);
 			break;
 		}
-- 
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