perf thread_map: Add thread_map event sythesize function

Introduce the perf_event__synthesize_thread_map2 function to synthesize
struct thread_map.

The perf_event__synthesize_thread_map name is already taken for
synthesizing the complete threads data (comm/mmap/fork).
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-5-git-send-email-jolsa@kernel.org
[ Rename thread_map_data_event to thread_map_event_entry ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/builtin-test.c

@@ -179,6 +179,10 @@ static struct test generic_tests[] = {
 			.get_desc	= test__bpf_subtest_get_desc,
 		},
 	},
+	{
+		.desc = "Test thread map synthesize",
+		.func = test__thread_map_synthesize,
+	},
 	{
 		.func = NULL,
 	},

tools/perf/tests/tests.h

@@ -79,6 +79,7 @@ int test__bpf(int subtest);
 const char *test__bpf_subtest_get_desc(int subtest);
 int test__bpf_subtest_get_nr(void);
 int test_session_topology(int subtest);
+int test__thread_map_synthesize(int subtest);
 
 #if defined(__arm__) || defined(__aarch64__)
 #ifdef HAVE_DWARF_UNWIND_SUPPORT

tools/perf/tests/thread-map.c

@@ -40,3 +40,32 @@ int test__thread_map(int subtest __maybe_unused)
 	thread_map__put(map);
 	return 0;
 }
+
+static int process_event(struct perf_tool *tool __maybe_unused,
+			 union perf_event *event,
+			 struct perf_sample *sample __maybe_unused,
+			 struct machine *machine __maybe_unused)
+{
+	struct thread_map_event *map = &event->thread_map;
+
+	TEST_ASSERT_VAL("wrong nr",   map->nr == 1);
+	TEST_ASSERT_VAL("wrong pid",  map->entries[0].pid == (u64) getpid());
+	TEST_ASSERT_VAL("wrong comm", !strcmp(map->entries[0].comm, "perf"));
+	return 0;
+}
+
+int test__thread_map_synthesize(int subtest __maybe_unused)
+{
+	struct thread_map *threads;
+
+	/* test map on current pid */
+	threads = thread_map__new_by_pid(getpid());
+	TEST_ASSERT_VAL("failed to alloc map", threads);
+
+	thread_map__read_comms(threads);
+
+	TEST_ASSERT_VAL("failed to synthesize map",
+		!perf_event__synthesize_thread_map2(NULL, threads, process_event, NULL));
+
+	return 0;
+}

tools/perf/util/event.c

@@ -700,6 +700,42 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
 	return err;
 }
 
+int perf_event__synthesize_thread_map2(struct perf_tool *tool,
+				      struct thread_map *threads,
+				      perf_event__handler_t process,
+				      struct machine *machine)
+{
+	union perf_event *event;
+	int i, err, size;
+
+	size  = sizeof(event->thread_map);
+	size +=	threads->nr * sizeof(event->thread_map.entries[0]);
+
+	event = zalloc(size);
+	if (!event)
+		return -ENOMEM;
+
+	event->header.type = PERF_RECORD_THREAD_MAP;
+	event->header.size = size;
+	event->thread_map.nr = threads->nr;
+
+	for (i = 0; i < threads->nr; i++) {
+		struct thread_map_event_entry *entry = &event->thread_map.entries[i];
+		char *comm = thread_map__comm(threads, i);
+
+		if (!comm)
+			comm = (char *) "";
+
+		entry->pid = thread_map__pid(threads, i);
+		strncpy((char *) &entry->comm, comm, sizeof(entry->comm));
+	}
+
+	err = process(tool, event, NULL, machine);
+
+	free(event);
+	return err;
+}
+
 size_t perf_event__fprintf_comm(union perf_event *event, FILE *fp)
 {
 	const char *s;

tools/perf/util/event.h

@@ -408,6 +408,10 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool,
 				      perf_event__handler_t process,
 				      struct machine *machine, bool mmap_data,
 				      unsigned int proc_map_timeout);
+int perf_event__synthesize_thread_map2(struct perf_tool *tool,
+				      struct thread_map *threads,
+				      perf_event__handler_t process,
+				      struct machine *machine);
 int perf_event__synthesize_threads(struct perf_tool *tool,
 				   perf_event__handler_t process,
 				   struct machine *machine, bool mmap_data,