trace-graph: Add new cmdlines via sched_switch

The cmdline cache used by ftrace only saves 100 cmdlines. But if
there's more tasks than cmdlines, then we will end up with a lot with
<...>. This looks at sched_switch and will add comms if they are found.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 16 insertions, 3 deletions

diff --git a/trace-graph.c b/trace-graph.c
index 1f5e4cf..48a41e6 100644
--- a/trace-graph.c
+++ b/trace-graph.c
@@ -705,7 +705,7 @@ static void draw_event_label(struct graph_info *ginfo, gint cpu,
 }
 
 static void draw_cpu(struct graph_info *ginfo, gint cpu,
-                     gint new_width)
+                     gint new_width, int read_comms)
 {
         static PangoFontDescription *font;
         PangoLayout *layout;
@@ -721,6 +721,7 @@ static void draw_cpu(struct graph_info *ginfo, gint cpu,
         gint p1 = 0, p2 = 0, p3 = 0;
         gint last_event_id = 0;
         gint event_id;
+        const char *comm;
 
         /* Calculate the size of 16 characters */
         if (!width_16) {
@@ -757,7 +758,17 @@ static void draw_cpu(struct graph_info *ginfo, gint cpu,
                 x = (gint)((gdouble)ts * ginfo->resolution);
 
 
-                if (!check_sched_switch(ginfo, record, &pid, NULL))
+                if (check_sched_switch(ginfo, record, &pid, &comm)) {
+                        if (read_comms) {
+                                /*
+                                 * First time through, register any missing
+                                 *  comm / pid mappings.
+                                 */
+                                if (!pevent_pid_is_registered(ginfo->pevent, pid))
+                                        pevent_register_comm(ginfo->pevent,
+                                                             strdup(comm), pid);
+                        }
+                } else
                         pid = pevent_data_pid(ginfo->pevent, record);
 
                 event_id = pevent_data_type(ginfo->pevent, record);
@@ -912,6 +923,7 @@ static void draw_timeline(struct graph_info *ginfo, gint width)
 static void draw_info(struct graph_info *ginfo,
                       gint new_width)
 {
+        static int read_comms = 1;
         gint cpu;
 
         ginfo->resolution = (gdouble)new_width / (gdouble)(ginfo->view_end_time -
@@ -921,8 +933,9 @@ static void draw_info(struct graph_info *ginfo,
 
         
         for (cpu = 0; cpu < ginfo->cpus; cpu++)
-                draw_cpu(ginfo, cpu, new_width);
+                draw_cpu(ginfo, cpu, new_width, read_comms);
 
+        read_comms = 0;
 }
 
 static gboolean