[PATCH v5 20/20] perf session: load data directory files for analysis

[Alexey Bayduraev]

Load data directory files and provide basic raw dump and aggregated
analysis support of data directories in report mode, still with no
memory consumption optimizations.

Design and implementation are based on the prototype [1], [2].

[1] git clone https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git -b perf/record_threads
[2] https://lore.kernel.org/lkml/20180913125450.21342-1-jolsa@xxxxxxxxxx/

Suggested-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@xxxxxxxxxxxxxxx>
---
 tools/perf/util/session.c | 127 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 47a414016510..1a741e6fc35b 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -65,6 +65,7 @@ struct reader_state {
 	u64	 data_size;
 	u64	 head;
 	bool	 eof;
+	u64	 size;
 };
 
 enum {
@@ -2316,6 +2317,7 @@ reader__read_event(struct reader *rd, struct perf_session *session,
 	if (skip)
 		size += skip;
 
+	st->size += size;
 	st->head += size;
 	st->file_pos += size;
 
@@ -2414,6 +2416,128 @@ static int __perf_session__process_events(struct perf_session *session)
 	return err;
 }
 
+/*
+ * This function reads, merge and process directory data.
+ * It assumens the version 1 of directory data, where each
+ * data file holds per-cpu data, already sorted by kernel.
+ */
+static int __perf_session__process_dir_events(struct perf_session *session)
+{
+	struct perf_data *data = session->data;
+	struct perf_tool *tool = session->tool;
+	int i, ret = 0, readers = 1;
+	struct ui_progress prog;
+	u64 total_size = perf_data__size(session->data);
+	struct reader *rd;
+
+	perf_tool__fill_defaults(tool);
+
+	ui_progress__init_size(&prog, total_size, "Sorting events...");
+
+	for (i = 0; i < data->dir.nr; i++) {
+		if (data->dir.files[i].size)
+			readers++;
+	}
+
+	rd = session->readers = zalloc(readers * sizeof(struct reader));
+	if (!rd)
+		return -ENOMEM;
+	session->nr_readers = readers;
+	readers = 0;
+
+	rd[readers] = (struct reader) {
+		.fd		= perf_data__fd(session->data),
+		.path		= session->data->file.path,
+		.data_size	= session->header.data_size,
+		.data_offset	= session->header.data_offset,
+	};
+	ret = reader__init(&rd[readers], NULL);
+	if (ret)
+		goto out_err;
+	ret = reader__mmap(&rd[readers], session);
+	if (ret != READER_OK) {
+		if (ret == READER_EOF)
+			ret = -EINVAL;
+		goto out_err;
+	}
+	readers++;
+
+	for (i = 0; i < data->dir.nr; i++) {
+		if (data->dir.files[i].size) {
+			rd[readers] = (struct reader) {
+				.fd		= data->dir.files[i].fd,
+				.path		= data->dir.files[i].path,
+				.data_size	= data->dir.files[i].size,
+				.data_offset	= 0,
+			};
+			ret = reader__init(&rd[readers], NULL);
+			if (ret)
+				goto out_err;
+			ret = reader__mmap(&rd[readers], session);
+			if (ret != READER_OK) {
+				if (ret == READER_EOF)
+					ret = -EINVAL;
+				goto out_err;
+			}
+			readers++;
+		}
+	}
+
+	i = 0;
+
+	while ((ret >= 0) && readers) {
+		if (session_done())
+			return 0;
+
+		if (rd[i].state.eof) {
+			i = (i + 1) % session->nr_readers;
+			continue;
+		}
+
+		ret = reader__read_event(&rd[i], session, &prog);
+		if (ret < 0)
+			break;
+		if (ret == READER_EOF) {
+			ret = reader__mmap(&rd[i], session);
+			if (ret < 0)
+				goto out_err;
+			if (ret == READER_EOF)
+				readers--;
+		}
+
+		/*
+		 * Processing 10MBs of data from each reader in sequence,
+		 * because that's the way the ordered events sorting works
+		 * most efficiently.
+		 */
+		if (rd[i].state.size >= 10*1024*1024) {
+			rd[i].state.size = 0;
+			i = (i + 1) % session->nr_readers;
+		}
+	}
+
+	ret = ordered_events__flush(&session->ordered_events, OE_FLUSH__FINAL);
+	if (ret)
+		goto out_err;
+
+	ret = perf_session__flush_thread_stacks(session);
+out_err:
+	ui_progress__finish();
+
+	if (!tool->no_warn)
+		perf_session__warn_about_errors(session);
+
+	/*
+	 * We may switching perf.data output, make ordered_events
+	 * reusable.
+	 */
+	ordered_events__reinit(&session->ordered_events);
+
+	session->one_mmap = false;
+
+	return ret;
+}
+
 int perf_session__process_events(struct perf_session *session)
 {
 	if (perf_session__register_idle_thread(session) < 0)
@@ -2422,6 +2546,9 @@ int perf_session__process_events(struct perf_session *session)
 	if (perf_data__is_pipe(session->data))
 		return __perf_session__process_pipe_events(session);
 
+	if (perf_data__is_dir(session->data))
+		return __perf_session__process_dir_events(session);
+
 	return __perf_session__process_events(session);
 }
 
-- 
2.19.0