parse-events: Make common_lock_depth optional

Some older kernels (and future ones) do not have the lock_depth
field in the event. Make it optional for parsing.

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

1 files changed, 21 insertions, 5 deletions

diff --git a/parse-events.c b/parse-events.c
index eabce41..30d3ea0 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -3116,6 +3116,8 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct event
 void pevent_data_lat_fmt(struct pevent *pevent,
                          struct trace_seq *s, struct record *record)
 {
+        static int check_lock_depth = 1;
+        static int lock_depth_exists;
         unsigned int lat_flags;
         unsigned int pc;
         int lock_depth;
@@ -3125,7 +3127,19 @@ void pevent_data_lat_fmt(struct pevent *pevent,
 
         lat_flags = parse_common_flags(pevent, data);
         pc = parse_common_pc(pevent, data);
-        lock_depth = parse_common_lock_depth(pevent, data);
+        /* lock_depth may not always exist */
+        if (check_lock_depth) {
+                struct format_field *field;
+                struct event_format *event;
+
+                check_lock_depth = 0;
+                event = pevent->event_list;
+                field = pevent_find_common_field(event, "common_lock_depth");
+                if (field)
+                        lock_depth_exists = 1;
+        }
+        if (lock_depth_exists)
+                lock_depth = parse_common_lock_depth(pevent, data);
 
         hardirq = lat_flags & TRACE_FLAG_HARDIRQ;
         softirq = lat_flags & TRACE_FLAG_SOFTIRQ;
@@ -3144,10 +3158,12 @@ void pevent_data_lat_fmt(struct pevent *pevent,
         else
                 trace_seq_putc(s, '.');
 
-        if (lock_depth < 0)
-                trace_seq_putc(s, '.');
-        else
-                trace_seq_printf(s, "%d", lock_depth);
+        if (lock_depth_exists) {
+                if (lock_depth < 0)
+                        trace_seq_putc(s, '.');
+                else
+                        trace_seq_printf(s, "%d", lock_depth);
+        }
 
         trace_seq_terminate(s);
 }