[PATCH 3/4] rtla: Add function to report missed events

[Tomas Glozar <tglozar@redhat.com>]

Add osnoise_report_missed_events to be used to report the number
of missed events either during or after an osnoise or timerlat run.
Also, display the percentage of missed events compared to the total
number of received events.

If an unknown number of missed events was reported during the run, the
entire number of missed events is reported as unknown.

Signed-off-by: Tomas Glozar <tglozar@redhat.com>
---
 tools/tracing/rtla/src/osnoise.c | 20 ++++++++++++++++++++
 tools/tracing/rtla/src/osnoise.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/tools/tracing/rtla/src/osnoise.c b/tools/tracing/rtla/src/osnoise.c
index 245e9344932b..eede5e01bff6 100644
--- a/tools/tracing/rtla/src/osnoise.c
+++ b/tools/tracing/rtla/src/osnoise.c
@@ -1079,6 +1079,26 @@ struct osnoise_tool *osnoise_init_trace_tool(char *tracer)
 	return NULL;
 }
 
+/*
+ * osnoise_report_missed_events - report number of events dropped by trace
+ * buffer
+ */
+void
+osnoise_report_missed_events(struct osnoise_tool *tool)
+{
+	unsigned long long total_events;
+
+	if (tool->trace.missed_events == UINT64_MAX)
+		printf("unknown number of events missed, results might not be accurate\n");
+	else if (tool->trace.missed_events > 0) {
+		total_events = tool->trace.processed_events + tool->trace.missed_events;
+
+		printf("%lld (%.2f%%) events missed, results might not be accurate\n",
+		       tool->trace.missed_events,
+		       (double) tool->trace.missed_events / total_events * 100.0);
+	}
+}
+
 static void osnoise_usage(int err)
 {
 	int i;
diff --git a/tools/tracing/rtla/src/osnoise.h b/tools/tracing/rtla/src/osnoise.h
index 555f4f4903cc..43e4b7bb7f4a 100644
--- a/tools/tracing/rtla/src/osnoise.h
+++ b/tools/tracing/rtla/src/osnoise.h
@@ -104,6 +104,7 @@ struct osnoise_tool {
 void osnoise_destroy_tool(struct osnoise_tool *top);
 struct osnoise_tool *osnoise_init_tool(char *tool_name);
 struct osnoise_tool *osnoise_init_trace_tool(char *tracer);
+void osnoise_report_missed_events(struct osnoise_tool *tool);
 
 int osnoise_hist_main(int argc, char *argv[]);
 int osnoise_top_main(int argc, char **argv);
-- 
2.48.1