1 files changed, 13 insertions, 5 deletions

diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 75aa97fbe1a1..fde652c9a511 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -36,7 +36,7 @@ static void __wakeup_reset(struct trace_array *tr);
 static int wakeup_graph_entry(struct ftrace_graph_ent *trace);
 static void wakeup_graph_return(struct ftrace_graph_ret *trace);
 
-static int save_lat_flag;
+static int save_flags;
 
 #define TRACE_DISPLAY_GRAPH     1
 
@@ -540,8 +540,11 @@ static void stop_wakeup_tracer(struct trace_array *tr)
 
 static int __wakeup_tracer_init(struct trace_array *tr)
 {
-        save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT;
-        trace_flags |= TRACE_ITER_LATENCY_FMT;
+        save_flags = trace_flags;
+
+        /* non overwrite screws up the latency tracers */
+        set_tracer_flag(TRACE_ITER_OVERWRITE, 1);
+        set_tracer_flag(TRACE_ITER_LATENCY_FMT, 1);
 
         tracing_max_latency = 0;
         wakeup_trace = tr;
@@ -563,12 +566,15 @@ static int wakeup_rt_tracer_init(struct trace_array *tr)
 
 static void wakeup_tracer_reset(struct trace_array *tr)
 {
+        int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
+        int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
+
         stop_wakeup_tracer(tr);
         /* make sure we put back any tasks we are tracing */
         wakeup_reset(tr);
 
-        if (!save_lat_flag)
-                trace_flags &= ~TRACE_ITER_LATENCY_FMT;
+        set_tracer_flag(TRACE_ITER_LATENCY_FMT, lat_flag);
+        set_tracer_flag(TRACE_ITER_OVERWRITE, overwrite_flag);
 }
 
 static void wakeup_tracer_start(struct trace_array *tr)
@@ -594,6 +600,7 @@ static struct tracer wakeup_tracer __read_mostly =
         .print_line     = wakeup_print_line,
         .flags          = &tracer_flags,
         .set_flag       = wakeup_set_flag,
+        .flag_changed   = trace_keep_overwrite,
 #ifdef CONFIG_FTRACE_SELFTEST
         .selftest    = trace_selftest_startup_wakeup,
 #endif
@@ -615,6 +622,7 @@ static struct tracer wakeup_rt_tracer __read_mostly =
         .print_line     = wakeup_print_line,
         .flags          = &tracer_flags,
         .set_flag       = wakeup_set_flag,
+        .flag_changed   = trace_keep_overwrite,
 #ifdef CONFIG_FTRACE_SELFTEST
         .selftest    = trace_selftest_startup_wakeup,
 #endif