[PATCH v2 06/15] perf session: load data directory into tool process memory

[Alexey Budankov]

Read trace files located in data directory into tool process memory.
Basic analysis support of data directories is provided for report
mode. Raw dump (-D) and aggregated reports are available for data
directories, still with no memory consumption optimizations. However
data directories collected with --compression-level option enabled
can be analyzed with little less memory because trace files are
unmaped from tool process memory after loading collected data.
The implementation is 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>
Suggested-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
---
 tools/perf/util/session.c | 48 +++++++++++++++++++++++++++++++++++++++
 tools/perf/util/session.h |  1 +
 2 files changed, 49 insertions(+)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 6afc670fdf0c..0752eec19813 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -2212,6 +2212,17 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 		goto more;
 
 out:
+	if (rd->unmap_file) {
+		int i;
+
+		for (i = 0; i < NUM_MMAPS; i++) {
+			if (mmaps[i]) {
+				munmap(mmaps[i], mmap_size);
+				mmaps[i] = NULL;
+			}
+		}
+	}
+
 	return err;
 }
 
@@ -2231,6 +2242,7 @@ static int __perf_session__process_events(struct perf_session *session)
 		.data_offset	= session->header.data_offset,
 		.process	= process_simple,
 		.path		= session->data->file.path,
+		.unmap_file	= false,
 	};
 	struct ordered_events *oe = &session->ordered_events;
 	struct perf_tool *tool = session->tool;
@@ -2247,6 +2259,42 @@ static int __perf_session__process_events(struct perf_session *session)
 	err = reader__process_events(&rd, session, &prog);
 	if (err)
 		goto out_err;
+
+	if (perf_data__is_dir(session->data)) {
+		int i, nr = session->data->dir.nr;
+		struct reader file_rd[nr];
+		u64 total_size = perf_data__size(session->data);
+
+		total_size -= session->data->file.size;
+		ui_progress__init_size(&prog, total_size, "Sorting events...");
+
+		memset(&file_rd, 0, nr * sizeof(file_rd[0]));
+
+		for (i = 0; i < nr ; i++) {
+			struct perf_data_file *file;
+
+			file = &session->data->dir.files[i];
+			file_rd[i] = (struct reader) {
+				.fd             = file->fd,
+				.path           = file->path,
+				.data_size      = file->size,
+				.data_offset    = 0,
+				.process	= process_simple,
+			};
+			file_rd[i].unmap_file = perf_header__has_feat(&session->header,
+								      HEADER_COMPRESSED);
+			session->reader = &file_rd[i];
+
+			if (zstd_init(&(file_rd[i].zstd_data), 0))
+				goto out_err;
+			err = reader__process_events(&file_rd[i], session, &prog);
+			zstd_fini(&(file_rd[i].zstd_data));
+			session->reader = NULL;
+			if (err)
+				goto out_err;
+		}
+	}
+
 	/* do the final flush for ordered samples */
 	err = ordered_events__flush(oe, OE_FLUSH__FINAL);
 	if (err)
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 4fc9ccdf7970..d428f3eaf7fd 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -43,6 +43,7 @@ struct reader {
 	u64		 data_offset;
 	reader_cb_t	 process;
 	struct zstd_data zstd_data;
+	bool		 unmap_file;
 };
 
 struct perf_session {
-- 
2.24.1