tracing/ftrace: types and naming corrections for sched tracer

Impact: cleanup This patch applies some corrections suggested by Steven Rostedt. Change the type of shed_ref into int since it is used into a Mutex, we don't need it anymore as an atomic variable in the sched_switch tracer. Also change the name of the register mutex. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>

tracing/ftrace: types and naming corrections for sched tracer
Impact: cleanup This patch applies some corrections suggested by Steven Rostedt. Change the type of shed_ref into int since it is used into a Mutex, we don't need it anymore as an atomic variable in the sched_switch tracer. Also change the name of the register mutex. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Frederic Weisbecker · Ingo Molnar
1 parent d7ad44b697
Showing 1 changed file with 13 additions and 17 deletions Side-by-side Diff
kernel/trace/trace_sched_switch.c
@@ -16,8 +16,8 @@
  
 static struct trace_array	*ctx_trace;
 static int __read_mostly	tracer_enabled;
-static atomic_t			sched_ref;
-static DEFINE_MUTEX(tracepoint_mutex);
+static int			sched_ref;
+static DEFINE_MUTEX(sched_register_mutex);
  
 static void
 probe_sched_switch(struct rq *__rq, struct task_struct *prev,
@@ -28,7 +28,7 @@
 	int cpu;
 	int pc;
  
-	if (!atomic_read(&sched_ref))
+	if (!sched_ref)
 		return;
  
 	tracing_record_cmdline(prev);
  
  
  
@@ -124,26 +124,22 @@
  
 static void tracing_start_sched_switch(void)
 {
-	long ref;
-
-	mutex_lock(&tracepoint_mutex);
-	tracer_enabled = 1;
-	ref = atomic_inc_return(&sched_ref);
-	if (ref == 1)
+	mutex_lock(&sched_register_mutex);
+	if (!(sched_ref++)) {
+		tracer_enabled = 1;
 		tracing_sched_register();
-	mutex_unlock(&tracepoint_mutex);
+	}
+	mutex_unlock(&sched_register_mutex);
 }
  
 static void tracing_stop_sched_switch(void)
 {
-	long ref;
-
-	mutex_lock(&tracepoint_mutex);
-	tracer_enabled = 0;
-	ref = atomic_dec_and_test(&sched_ref);
-	if (ref)
+	mutex_lock(&sched_register_mutex);
+	if (!(--sched_ref)) {
 		tracing_sched_unregister();
-	mutex_unlock(&tracepoint_mutex);
+		tracer_enabled = 0;
+	}
+	mutex_unlock(&sched_register_mutex);
 }
  
 void tracing_start_cmdline_record(void)
...	...	@@ -16,8 +16,8 @@
16	16
17	17	static struct trace_array *ctx_trace;
18	18	static int __read_mostly tracer_enabled;
19		-static atomic_t sched_ref;
20		-static DEFINE_MUTEX(tracepoint_mutex);
	19	+static int sched_ref;
	20	+static DEFINE_MUTEX(sched_register_mutex);
21	21
22	22	static void
23	23	probe_sched_switch(struct rq __rq, struct task_struct prev,
...	...	@@ -28,7 +28,7 @@
28	28	int cpu;
29	29	int pc;
30	30
31		- if (!atomic_read(&sched_ref))
	31	+ if (!sched_ref)
32	32	return;
33	33
34	34	tracing_record_cmdline(prev);
35	35
36	36
37	37
...	...	@@ -124,26 +124,22 @@
124	124
125	125	static void tracing_start_sched_switch(void)
126	126	{
127		- long ref;
128		-
129		- mutex_lock(&tracepoint_mutex);
130		- tracer_enabled = 1;
131		- ref = atomic_inc_return(&sched_ref);
132		- if (ref == 1)
	127	+ mutex_lock(&sched_register_mutex);
	128	+ if (!(sched_ref++)) {
	129	+ tracer_enabled = 1;
133	130	tracing_sched_register();
134		- mutex_unlock(&tracepoint_mutex);
	131	+ }
	132	+ mutex_unlock(&sched_register_mutex);
135	133	}
136	134
137	135	static void tracing_stop_sched_switch(void)
138	136	{
139		- long ref;
140		-
141		- mutex_lock(&tracepoint_mutex);
142		- tracer_enabled = 0;
143		- ref = atomic_dec_and_test(&sched_ref);
144		- if (ref)
	137	+ mutex_lock(&sched_register_mutex);
	138	+ if (!(--sched_ref)) {
145	139	tracing_sched_unregister();
146		- mutex_unlock(&tracepoint_mutex);
	140	+ tracer_enabled = 0;
	141	+ }
	142	+ mutex_unlock(&sched_register_mutex);
147	143	}
148	144
149	145	void tracing_start_cmdline_record(void)