[PATCH 4/5] perf record: Add finished init event

[Adrian Hunter]

In preparation for recording sideband events in a virtual machine guest so
that they can be injected into a host perf.data file.

This is needed to enable injecting events after the initial synthesized
user events (that have an all zero id sample) but before regular events.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 tools/lib/perf/include/perf/event.h |  1 +
 tools/perf/builtin-inject.c         |  1 +
 tools/perf/builtin-record.c         | 27 +++++++++++++++++++++++++++
 tools/perf/util/event.c             |  1 +
 tools/perf/util/session.c           |  4 ++++
 tools/perf/util/tool.h              |  3 ++-
 6 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index e7758707cadd..9f7ca070da87 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -389,6 +389,7 @@ enum perf_user_event_type { /* above any possible kernel type */
 	PERF_RECORD_TIME_CONV			= 79,
 	PERF_RECORD_HEADER_FEATURE		= 80,
 	PERF_RECORD_COMPRESSED			= 81,
+	PERF_RECORD_FINISHED_INIT		= 82,
 	PERF_RECORD_HEADER_MAX
 };
 
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index a75bf11585b5..42e2918fd1cc 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -1059,6 +1059,7 @@ int cmd_inject(int argc, const char **argv)
 			.stat		= perf_event__repipe_op2_synth,
 			.stat_round	= perf_event__repipe_op2_synth,
 			.feature	= perf_event__repipe_op2_synth,
+			.finished_init	= perf_event__repipe_op2_synth,
 			.compressed	= perf_event__repipe_op4_synth,
 			.auxtrace	= perf_event__repipe_auxtrace,
 		},
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 40dca1fba4e3..cf5c5379ceaa 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1388,6 +1388,11 @@ static struct perf_event_header finished_round_event = {
 	.type = PERF_RECORD_FINISHED_ROUND,
 };
 
+static struct perf_event_header finished_init_event = {
+	.size = sizeof(struct perf_event_header),
+	.type = PERF_RECORD_FINISHED_INIT,
+};
+
 static void record__adjust_affinity(struct record *rec, struct mmap *map)
 {
 	if (rec->opts.affinity != PERF_AFFINITY_SYS &&
@@ -1696,6 +1701,14 @@ static int record__synthesize_workload(struct record *rec, bool tail)
 	return err;
 }
 
+static int write_finished_init(struct record *rec, bool tail)
+{
+	if (rec->opts.tail_synthesize != tail)
+		return 0;
+
+	return record__write(rec, NULL, &finished_init_event, sizeof(finished_init_event));
+}
+
 static int record__synthesize(struct record *rec, bool tail);
 
 static int
@@ -1710,6 +1723,8 @@ record__switch_output(struct record *rec, bool at_exit)
 
 	record__aio_mmap_read_sync(rec);
 
+	write_finished_init(rec, true);
+
 	record__synthesize(rec, true);
 	if (target__none(&rec->opts.target))
 		record__synthesize_workload(rec, true);
@@ -1764,6 +1779,7 @@ record__switch_output(struct record *rec, bool at_exit)
 		 */
 		if (target__none(&rec->opts.target))
 			record__synthesize_workload(rec, false);
+		write_finished_init(rec, false);
 	}
 	return fd;
 }
@@ -2419,6 +2435,15 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	trigger_ready(&auxtrace_snapshot_trigger);
 	trigger_ready(&switch_output_trigger);
 	perf_hooks__invoke_record_start();
+
+	/*
+	 * Must write FINISHED_INIT so it will be seen after all other
+	 * synthesized user events, but before any regular events.
+	 */
+	err = write_finished_init(rec, false);
+	if (err < 0)
+		goto out_child;
+
 	for (;;) {
 		unsigned long long hits = thread->samples;
 
@@ -2563,6 +2588,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 		fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n",
 			record__waking(rec));
 
+	write_finished_init(rec, true);
+
 	if (target__none(&rec->opts.target))
 		record__synthesize_workload(rec, true);
 
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 0476bb3a4188..1fa14598b916 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -76,6 +76,7 @@ static const char *perf_event__names[] = {
 	[PERF_RECORD_TIME_CONV]			= "TIME_CONV",
 	[PERF_RECORD_HEADER_FEATURE]		= "FEATURE",
 	[PERF_RECORD_COMPRESSED]		= "COMPRESSED",
+	[PERF_RECORD_FINISHED_INIT]		= "FINISHED_INIT",
 };
 
 const char *perf_event__name(unsigned int id)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 0aa818977d2b..37f833c3c81b 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -562,6 +562,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->feature = process_event_op2_stub;
 	if (tool->compressed == NULL)
 		tool->compressed = perf_session__process_compressed_event;
+	if (tool->finished_init == NULL)
+		tool->finished_init = process_event_op2_stub;
 }
 
 static void swap_sample_id_all(union perf_event *event, void *data)
@@ -1706,6 +1708,8 @@ static s64 perf_session__process_user_event(struct perf_session *session,
 		if (err)
 			dump_event(session->evlist, event, file_offset, &sample, file_path);
 		return err;
+	case PERF_RECORD_FINISHED_INIT:
+		return tool->finished_init(session, event);
 	default:
 		return -EINVAL;
 	}
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index f2352dba1875..c957fb849ac6 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -76,7 +76,8 @@ struct perf_tool {
 			stat_config,
 			stat,
 			stat_round,
-			feature;
+			feature,
+			finished_init;
 	event_op4	compressed;
 	event_op3	auxtrace;
 	bool		ordered_events;
-- 
2.25.1