trace: Call tracing_reset_online_cpus before tracer->init()

Impact: cleanup

To make it easy for ftrace plugin writers, as this was open coded in
the existing plugins

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Frédéric Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

11 files changed, 25 insertions, 47 deletions

diff --git a/block/blktrace.c b/block/blktrace.c
index 834cd84037b2..ca6d32061e4f 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -1086,8 +1086,6 @@ static void blk_tracer_print_header(struct seq_file *m)
 
 static void blk_tracer_start(struct trace_array *tr)
 {
-        tracing_reset_online_cpus(tr);
-
         mutex_lock(&blk_probe_mutex);
         if (atomic_add_return(1, &blk_probes_ref) == 1)
                 if (blk_register_tracepoints())
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8fad3776e843..ef4dbac95568 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2171,6 +2171,12 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf,
         return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
+int tracer_init(struct tracer *t, struct trace_array *tr)
+{
+        tracing_reset_online_cpus(tr);
+        return t->init(tr);
+}
+
 static int tracing_set_tracer(const char *buf)
 {
         struct trace_array *tr = &global_trace;
@@ -2195,7 +2201,7 @@ static int tracing_set_tracer(const char *buf)
 
         current_trace = t;
         if (t->init) {
-                ret = t->init(tr);
+                ret = tracer_init(t, tr);
                 if (ret)
                         goto out;
         }
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index e03f157c772e..f2742fb1575a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -395,6 +395,7 @@ struct trace_iterator {
         cpumask_var_t           started;
 };
 
+int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
 void trace_wake_up(void);
 void tracing_reset(struct trace_array *tr, int cpu);
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 48b2196abe37..f8ae2c50e01d 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -131,7 +131,6 @@ static void stop_branch_trace(struct trace_array *tr)
 
 static int branch_trace_init(struct trace_array *tr)
 {
-        tracing_reset_online_cpus(tr);
         start_branch_trace(tr);
         return 0;
 }
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index d067cea2ccc3..36bf9568ccd9 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -24,32 +24,21 @@ static struct trace_array	*func_trace;
 static void tracing_start_function_trace(void);
 static void tracing_stop_function_trace(void);
 
-static void start_function_trace(struct trace_array *tr)
+static int function_trace_init(struct trace_array *tr)
 {
         func_trace = tr;
         tr->cpu = get_cpu();
-        tracing_reset_online_cpus(tr);
         put_cpu();
 
         tracing_start_cmdline_record();
         tracing_start_function_trace();
-}
-
-static void stop_function_trace(struct trace_array *tr)
-{
-        tracing_stop_function_trace();
-        tracing_stop_cmdline_record();
-}
-
-static int function_trace_init(struct trace_array *tr)
-{
-        start_function_trace(tr);
         return 0;
 }
 
 static void function_trace_reset(struct trace_array *tr)
 {
-        stop_function_trace(tr);
+        tracing_stop_function_trace();
+        tracing_stop_cmdline_record();
 }
 
 static void function_trace_start(struct trace_array *tr)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index c97594d826bc..222f97d336a6 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -56,7 +56,6 @@ static int graph_trace_init(struct trace_array *tr)
                                         &trace_graph_entry);
         if (ret)
                 return ret;
-        tracing_reset_online_cpus(tr);
         tracing_start_cmdline_record();
 
         return 0;
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index 2aa1c9f4c7d8..ca4bbcfb9e2c 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -132,7 +132,6 @@ static int bts_trace_init(struct trace_array *tr)
         hw_branch_trace = tr;
 
         register_hotcpu_notifier(&bts_hotcpu_notifier);
-        tracing_reset_online_cpus(tr);
         bts_trace_start(tr);
 
         return 0;
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 087b6cbf4ea5..9aa84bde23cd 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -48,7 +48,6 @@ static void stop_nop_trace(struct trace_array *tr)
 static int nop_trace_init(struct trace_array *tr)
 {
         ctx_trace = tr;
-        tracing_reset_online_cpus(tr);
         start_nop_trace(tr);
         return 0;
 }
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index c4f9add5ec90..30e14fe85896 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -185,12 +185,6 @@ void tracing_sched_switch_assign_trace(struct trace_array *tr)
         ctx_trace = tr;
 }
 
-static void start_sched_trace(struct trace_array *tr)
-{
-        tracing_reset_online_cpus(tr);
-        tracing_start_sched_switch_record();
-}
-
 static void stop_sched_trace(struct trace_array *tr)
 {
         tracing_stop_sched_switch_record();
@@ -199,7 +193,7 @@ static void stop_sched_trace(struct trace_array *tr)
 static int sched_switch_trace_init(struct trace_array *tr)
 {
         ctx_trace = tr;
-        start_sched_trace(tr);
+        tracing_start_sched_switch_record();
         return 0;
 }
 
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 5013812578b1..445700e51f6d 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -115,7 +115,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
         ftrace_set_filter(func_name, strlen(func_name), 1);
 
         /* enable tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 goto out;
@@ -189,7 +189,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
         ftrace_enabled = 1;
         tracer_enabled = 1;
 
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 goto out;
@@ -236,7 +236,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
         int ret;
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 return ret;
@@ -290,7 +290,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
         }
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 return ret;
@@ -344,7 +344,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
         }
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 goto out;
@@ -476,7 +476,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
         wait_for_completion(&isrt);
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 return ret;
@@ -537,7 +537,7 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
         int ret;
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 return ret;
@@ -569,7 +569,7 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
         int ret;
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 return 0;
@@ -596,7 +596,7 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
         int ret;
 
         /* start the tracing */
-        ret = trace->init(tr);
+        ret = tracer_init(trace, tr);
         if (ret) {
                 warn_failed_init_tracer(trace, ret);
                 return ret;
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index eaca5ad803ff..84ca9d81e74d 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -226,15 +226,6 @@ static void stop_stack_timers(void)
                 stop_stack_timer(cpu);
 }
 
-static void start_stack_trace(struct trace_array *tr)
-{
-        mutex_lock(&sample_timer_lock);
-        tracing_reset_online_cpus(tr);
-        start_stack_timers();
-        tracer_enabled = 1;
-        mutex_unlock(&sample_timer_lock);
-}
-
 static void stop_stack_trace(struct trace_array *tr)
 {
         mutex_lock(&sample_timer_lock);
@@ -247,7 +238,10 @@ static int stack_trace_init(struct trace_array *tr)
 {
         sysprof_trace = tr;
 
-        start_stack_trace(tr);
+        mutex_lock(&sample_timer_lock);
+        start_stack_timers();
+        tracer_enabled = 1;
+        mutex_unlock(&sample_timer_lock);
         return 0;
 }