1 files changed, 39 insertions, 31 deletions

diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 3ae93f16b565..0067b49746c1 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -50,8 +50,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
                 return;
 
         pc = preempt_count();
-        resched = need_resched();
-        preempt_disable_notrace();
+        resched = ftrace_preempt_disable();
 
         cpu = raw_smp_processor_id();
         data = tr->data[cpu];
@@ -81,15 +80,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
  out:
         atomic_dec(&data->disabled);
 
-        /*
-         * To prevent recursion from the scheduler, if the
-         * resched flag was set before we entered, then
-         * don't reschedule.
-         */
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        ftrace_preempt_enable(resched);
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
@@ -271,6 +262,12 @@ out:
         atomic_dec(&wakeup_trace->data[cpu]->disabled);
 }
 
+/*
+ * save_tracer_enabled is used to save the state of the tracer_enabled
+ * variable when we disable it when we open a trace output file.
+ */
+static int save_tracer_enabled;
+
 static void start_wakeup_tracer(struct trace_array *tr)
 {
         int ret;
@@ -309,7 +306,13 @@ static void start_wakeup_tracer(struct trace_array *tr)
 
         register_ftrace_function(&trace_ops);
 
-        tracer_enabled = 1;
+        if (tracing_is_enabled()) {
+                tracer_enabled = 1;
+                save_tracer_enabled = 1;
+        } else {
+                tracer_enabled = 0;
+                save_tracer_enabled = 0;
+        }
 
         return;
 fail_deprobe_wake_new:
@@ -321,49 +324,53 @@ fail_deprobe:
 static void stop_wakeup_tracer(struct trace_array *tr)
 {
         tracer_enabled = 0;
+        save_tracer_enabled = 0;
         unregister_ftrace_function(&trace_ops);
         unregister_trace_sched_switch(probe_wakeup_sched_switch);
         unregister_trace_sched_wakeup_new(probe_wakeup);
         unregister_trace_sched_wakeup(probe_wakeup);
 }
 
-static void wakeup_tracer_init(struct trace_array *tr)
+static int wakeup_tracer_init(struct trace_array *tr)
 {
         wakeup_trace = tr;
-
-        if (tr->ctrl)
-                start_wakeup_tracer(tr);
+        start_wakeup_tracer(tr);
+        return 0;
 }
 
 static void wakeup_tracer_reset(struct trace_array *tr)
 {
-        if (tr->ctrl) {
-                stop_wakeup_tracer(tr);
-                /* make sure we put back any tasks we are tracing */
-                wakeup_reset(tr);
-        }
+        stop_wakeup_tracer(tr);
+        /* make sure we put back any tasks we are tracing */
+        wakeup_reset(tr);
+}
+
+static void wakeup_tracer_start(struct trace_array *tr)
+{
+        wakeup_reset(tr);
+        tracer_enabled = 1;
+        save_tracer_enabled = 1;
 }
 
-static void wakeup_tracer_ctrl_update(struct trace_array *tr)
+static void wakeup_tracer_stop(struct trace_array *tr)
 {
-        if (tr->ctrl)
-                start_wakeup_tracer(tr);
-        else
-                stop_wakeup_tracer(tr);
+        tracer_enabled = 0;
+        save_tracer_enabled = 0;
 }
 
 static void wakeup_tracer_open(struct trace_iterator *iter)
 {
         /* stop the trace while dumping */
-        if (iter->tr->ctrl)
-                stop_wakeup_tracer(iter->tr);
+        tracer_enabled = 0;
 }
 
 static void wakeup_tracer_close(struct trace_iterator *iter)
 {
         /* forget about any processes we were recording */
-        if (iter->tr->ctrl)
-                start_wakeup_tracer(iter->tr);
+        if (save_tracer_enabled) {
+                wakeup_reset(iter->tr);
+                tracer_enabled = 1;
+        }
 }
 
 static struct tracer wakeup_tracer __read_mostly =
@@ -371,9 +378,10 @@ static struct tracer wakeup_tracer __read_mostly =
         .name           = "wakeup",
         .init           = wakeup_tracer_init,
         .reset          = wakeup_tracer_reset,
+        .start          = wakeup_tracer_start,
+        .stop           = wakeup_tracer_stop,
         .open           = wakeup_tracer_open,
         .close          = wakeup_tracer_close,
-        .ctrl_update    = wakeup_tracer_ctrl_update,
         .print_max      = 1,
 #ifdef CONFIG_FTRACE_SELFTEST
         .selftest    = trace_selftest_startup_wakeup,