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

Alexey Budankov
2020-10-21T16:01:26Z

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@kernel.org/

Suggested-by: Jiri Olsa <jolsa@kernel.org>
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
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