[PATCH 14/14] perf script: show overhead events

[kan . liang]

From: Kan Liang <kan.liang@xxxxxxxxx>

Introduce a new option --show-overhead to show overhead events in perf
script

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
---
 tools/perf/builtin-script.c | 36 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/event.c     | 37 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/event.h     |  1 +
 3 files changed, 74 insertions(+)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index e1daff3..76d9747 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -829,6 +829,7 @@ struct perf_script {
 	bool			show_task_events;
 	bool			show_mmap_events;
 	bool			show_switch_events;
+	bool			show_overhead;
 	bool			allocated;
 	struct cpu_map		*cpus;
 	struct thread_map	*threads;
@@ -1264,6 +1265,37 @@ static int process_switch_event(struct perf_tool *tool,
 	return 0;
 }
 
+static int process_overhead_event(struct perf_tool *tool,
+				  union perf_event *event,
+				  struct perf_sample *sample,
+				  struct machine *machine)
+{
+	struct thread *thread;
+	struct perf_script *script = container_of(tool, struct perf_script, tool);
+	struct perf_session *session = script->session;
+	struct perf_evsel *evsel;
+
+	if (perf_event__process_switch(tool, event, sample, machine) < 0)
+		return -1;
+	if (sample) {
+		evsel = perf_evlist__id2evsel(session->evlist, sample->id);
+		thread = machine__findnew_thread(machine, sample->pid, sample->tid);
+		if (thread == NULL) {
+			pr_debug("problem processing OVERHEAD event, skipping it.\n");
+			return -1;
+		}
+
+		print_sample_start(sample, thread, evsel);
+		perf_event__fprintf(event, stdout);
+		thread__put(thread);
+	} else {
+		/* USER OVERHEAD event */
+		perf_event__fprintf(event, stdout);
+	}
+
+	return 0;
+}
+
 static void sig_handler(int sig __maybe_unused)
 {
 	session_done = 1;
@@ -1287,6 +1319,8 @@ static int __cmd_script(struct perf_script *script)
 	}
 	if (script->show_switch_events)
 		script->tool.context_switch = process_switch_event;
+	if (script->show_overhead)
+		script->tool.overhead  = process_overhead_event;
 
 	ret = perf_session__process_events(script->session);
 
@@ -2172,6 +2206,8 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
 		    "Show the mmap events"),
 	OPT_BOOLEAN('\0', "show-switch-events", &script.show_switch_events,
 		    "Show context switch events (if recorded)"),
+	OPT_BOOLEAN('\0', "show-overhead", &script.show_overhead,
+		    "Show overhead events"),
 	OPT_BOOLEAN('f', "force", &file.force, "don't complain, do it"),
 	OPT_BOOLEAN(0, "ns", &nanosecs,
 		    "Use 9 decimal places when displaying time"),
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 6cd43c9..cd4f3aa 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -1190,6 +1190,39 @@ size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp)
 		       event->context_switch.next_prev_tid);
 }
 
+size_t perf_event__fprintf_overhead(union perf_event *event, FILE *fp)
+{
+	size_t ret;
+
+	if (event->overhead.type == PERF_NMI_OVERHEAD) {
+		ret = fprintf(fp, " [NMI] nr: %llu  time: %llu cpu %u\n",
+			      event->overhead.entry.nr,
+			      event->overhead.entry.time,
+			      event->overhead.entry.cpu);
+	} else if (event->overhead.type == PERF_MUX_OVERHEAD) {
+		ret = fprintf(fp, " [MUX] nr: %llu  time: %llu cpu %u\n",
+			      event->overhead.entry.nr,
+			      event->overhead.entry.time,
+			      event->overhead.entry.cpu);
+	} else if (event->overhead.type == PERF_SB_OVERHEAD) {
+		ret = fprintf(fp, " [SB] nr: %llu  time: %llu cpu %u\n",
+			      event->overhead.entry.nr,
+			      event->overhead.entry.time,
+			      event->overhead.entry.cpu);
+	} else if (event->overhead.type == PERF_USER_WRITE_OVERHEAD) {
+		ret = fprintf(fp, " [USER WRITE] nr: %llu  time: %llu cpu %u\n",
+			      event->overhead.entry.nr,
+			      event->overhead.entry.time,
+			      event->overhead.entry.cpu);
+	} else if (event->overhead.type == PERF_USER_ELAPSED_TIME) {
+		ret = fprintf(fp, " [ELAPSED TIME] time: %llu\n",
+			      event->overhead.entry.time);
+	} else {
+		ret = fprintf(fp, " unhandled!\n");
+	}
+	return ret;
+}
+
 size_t perf_event__fprintf(union perf_event *event, FILE *fp)
 {
 	size_t ret = fprintf(fp, "PERF_RECORD_%s",
@@ -1219,6 +1252,10 @@ size_t perf_event__fprintf(union perf_event *event, FILE *fp)
 	case PERF_RECORD_SWITCH_CPU_WIDE:
 		ret += perf_event__fprintf_switch(event, fp);
 		break;
+	case PERF_RECORD_OVERHEAD:
+	case PERF_RECORD_USER_OVERHEAD:
+		ret += perf_event__fprintf_overhead(event, fp);
+		break;
 	default:
 		ret += fprintf(fp, "\n");
 	}
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index ceb0968..36e295d 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -690,6 +690,7 @@ size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_thread_map(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_cpu_map(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf(union perf_event *event, FILE *fp);
+size_t perf_event__fprintf_overhead(union perf_event *event, FILE *fp);
 
 u64 kallsyms__get_function_start(const char *kallsyms_filename,
 				 const char *symbol_name);
-- 
2.5.5