1 files changed, 13 insertions, 0 deletions

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 2eefb33c967..77f556f7604 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -11,6 +11,8 @@
 
 static char const               *script_name;
 static char const               *generate_script_lang;
+static bool                     debug_ordering;
+static u64                      last_timestamp;
 
 static int default_start_script(const char *script __unused,
                                 int argc __unused,
@@ -87,6 +89,14 @@ static int process_sample_event(event_t *event, struct perf_session *session)
         }
 
         if (session->sample_type & PERF_SAMPLE_RAW) {
+                if (debug_ordering) {
+                        if (data.time < last_timestamp) {
+                                pr_err("Samples misordered, previous: %llu "
+                                        "this: %llu\n", last_timestamp,
+                                        data.time);
+                        }
+                        last_timestamp = data.time;
+                }
                 /*
                  * FIXME: better resolve from pid from the struct trace_entry
                  * field, although it should be the same than this perf
@@ -108,6 +118,7 @@ static struct perf_event_ops event_ops = {
         .event_type = event__process_event_type,
         .tracing_data = event__process_tracing_data,
         .build_id = event__process_build_id,
+        .ordered_samples = true,
 };
 
 extern volatile int session_done;
@@ -531,6 +542,8 @@ static const struct option options[] = {
                    "generate perf-trace.xx script in specified language"),
         OPT_STRING('i', "input", &input_name, "file",
                     "input file name"),
+        OPT_BOOLEAN('d', "debug-ordering", &debug_ordering,
+                   "check that samples time ordering is monotonic"),
 
         OPT_END()
 };