Adding perf.data-directory-format.txt to describe the directory data layout.
Link: http://lkml.kernel.org/n/tip-1c8u1thx63v2ldwfdas4x...@git.kernel.org Signed-off-by: Jiri Olsa <jo...@kernel.org> --- .../perf.data-directory-format.txt | 54 +++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 tools/perf/Documentation/perf.data-directory-format.txt diff --git a/tools/perf/Documentation/perf.data-directory-format.txt b/tools/perf/Documentation/perf.data-directory-format.txt new file mode 100644 index 000000000000..bbd6d31b10c8 --- /dev/null +++ b/tools/perf/Documentation/perf.data-directory-format.txt @@ -0,0 +1,54 @@ +perf.data directory format + +DISCLAIMER This is not ABI yet and is subject to possible change + in following versions of perf. We will remove this + disclaimer once the directory format soaks in. + + +This document describes the on-disk perf.data format, generated +by perf record with --dir option and consumed by the other perf +tools. + +The directory perf.data is created by perf record command by +using the --dir option: + + $ perf record --dir perf bench sched messaging + $ ls -l perf.data + total 344 + -rw-------. 1 jolsa jolsa 43864 Jan 20 22:26 data.0 + -rw-------. 1 jolsa jolsa 30464 Jan 20 22:26 data.1 + -rw-------. 1 jolsa jolsa 53816 Jan 20 22:26 data.2 + -rw-------. 1 jolsa jolsa 30368 Jan 20 22:26 data.3 + -rw-------. 1 jolsa jolsa 40088 Jan 20 22:26 data.4 + -rw-------. 1 jolsa jolsa 42592 Jan 20 22:26 data.5 + -rw-------. 1 jolsa jolsa 56136 Jan 20 22:26 data.6 + -rw-------. 1 jolsa jolsa 25992 Jan 20 22:26 data.7 + -rw-------. 1 jolsa jolsa 8832 Jan 20 22:26 header + +The header file keeps the standard perf.data file header, +and the data.* files keep data. + +header file +----------- +The header file following the standard format describe in +Documentation/perf.data-file-format doc. Including its data +portion that is used to store manually synthesized events. + +data file +--------- +The data files layout is described by HEADER_DIR_FORMAT feature. +Currently it holds only version number (1): + + HEADER_DIR_FORMAT = 24 + + struct { + uint64_t version; + } + +The current only only version value 1 means that data files: + - follow the 'data.*' format + - contain raw events data in standard perf format as read + from kernel (and need to be sorted) + +Future versions are expected to describe different data files +layout according to special needs. -- 2.17.2