4 files changed, 40 insertions, 2 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b24a72d35008..b296186eb93a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2140,6 +2140,21 @@ enum print_line_t print_trace_line(struct trace_iterator *iter)
         return print_trace_fmt(iter);
 }
 
+void trace_latency_header(struct seq_file *m)
+{
+        struct trace_iterator *iter = m->private;
+
+        /* print nothing if the buffers are empty */
+        if (trace_empty(iter))
+                return;
+
+        if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+                print_trace_header(m, iter);
+
+        if (!(trace_flags & TRACE_ITER_VERBOSE))
+                print_lat_help_header(m);
+}
+
 void trace_default_header(struct seq_file *m)
 {
         struct trace_iterator *iter = m->private;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 092e1f8d18dc..f8ec2291b522 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -370,6 +370,7 @@ void trace_graph_function(struct trace_array *tr,
                     unsigned long ip,
                     unsigned long parent_ip,
                     unsigned long flags, int pc);
+void trace_latency_header(struct seq_file *m);
 void trace_default_header(struct seq_file *m);
 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 int trace_empty(struct trace_iterator *iter);
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index a1a3359996a7..a248c686b2b8 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -280,9 +280,20 @@ static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 }
 
 static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { }
-static void irqsoff_print_header(struct seq_file *s) { }
 static void irqsoff_trace_open(struct trace_iterator *iter) { }
 static void irqsoff_trace_close(struct trace_iterator *iter) { }
+
+#ifdef CONFIG_FUNCTION_TRACER
+static void irqsoff_print_header(struct seq_file *s)
+{
+        trace_default_header(s);
+}
+#else
+static void irqsoff_print_header(struct seq_file *s)
+{
+        trace_latency_header(s);
+}
+#endif /* CONFIG_FUNCTION_TRACER */
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 /*
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index e4a70c0c71b6..ff791ea48b57 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -280,9 +280,20 @@ static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
 }
 
 static void wakeup_graph_return(struct ftrace_graph_ret *trace) { }
-static void wakeup_print_header(struct seq_file *s) { }
 static void wakeup_trace_open(struct trace_iterator *iter) { }
 static void wakeup_trace_close(struct trace_iterator *iter) { }
+
+#ifdef CONFIG_FUNCTION_TRACER
+static void wakeup_print_header(struct seq_file *s)
+{
+        trace_default_header(s);
+}
+#else
+static void wakeup_print_header(struct seq_file *s)
+{
+        trace_latency_header(s);
+}
+#endif /* CONFIG_FUNCTION_TRACER */
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 /*