(This is a rebased and updated version of Stephane Eranian's version
in https://patchwork.kernel.org/patch/1499081/)
Up until now, meta-data was only available when perf record
was used in "regular" mode, i.e., generating a perf.data file.
For users depending on pipe mode, neither host or event header
information were gathered. This patch addresses this limitation.
The difficulty in pipe mode is that information needs to be written
sequentially to the pipe. Meta data headers are usually generated
(and also expected) at the beginning of the file (or piped output).
To solve this problem, we introduce new synthetic record types,
one for each meta-data type. The approach is similar to what
is *ALREADY* used for BUILD_ID and TRACING_DATA.
We have modified util/header.c such that the same routines are used
to generate and read the meta-data information regardless of pipe-mode
vs. regular mode. To make this work, we added a new struct called
feat_fd which encapsulates all the information necessary to read or
write meta-data information to a file/pipe or from a file/pipe.
With this patch, it is possible to get:
$ perf record -o - -e cycles -c 10 sleep 1 | perf report --stdio
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.000 MB - ]
# hostname : myhost
# os release : 4.11.0-dbx-up_perf
# perf version : 4.11.rc6.g6277c80
# arch : x86_64
# nrcpus online : 72
# nrcpus avail : 72
# cpudesc : Intel(R) Xeon(R) CPU E5-2696 v3 @ 2.30GHz
# cpuid : GenuineIntel,6,63,2
# total memory : 263457192 kB
# cmdline : /root/perf record -o - -e cycles -c 10 sleep 1
# HEADER_CPU_TOPOLOGY info available, use -I to display
# HEADER_NUMA_TOPOLOGY info available, use -I to display
# pmu mappings: intel_bts = 6, uncore_imc_4 = 22, uncore_sbox_1 = 47,
uncore_cbox_5 = 33, uncore_ha_0 = 16, uncore_cbox
Percent | Source code & Disassembly of kcore for cycles (9 samples)
...
David Carrillo-Cisneros (7):
perf header: fail on write_padded error
perf util: add const modifier to buf in "writen" function
perf header: use struct feat_fd for write
perf header: use struct feat_fd for print
perf header: use struct feat_fd for process and read
perf tool: make show-info in perf report a tool attribute
perf tools: add feature header record to pipe-mode
tools/perf/builtin-annotate.c | 1 +
tools/perf/builtin-inject.c | 1 +
tools/perf/builtin-record.c | 6 +
tools/perf/builtin-report.c | 6 +-
tools/perf/builtin-script.c | 6 +-
tools/perf/util/build-id.c| 10 +-
tools/perf/util/build-id.h| 4 +-
tools/perf/util/event.c | 13 +
tools/perf/util/event.h | 19 +
tools/perf/util/header.c | 905 +++---
tools/perf/util/header.h | 17 +-
tools/perf/util/session.c | 12 +
tools/perf/util/tool.h| 4 +-
tools/perf/util/util.c| 6 +-
tools/perf/util/util.h| 2 +-
15 files changed, 594 insertions(+), 418 deletions(-)
--
2.13.0.303.g4ebf302169-goog
