kernel_optimize_test/tools/perf/Documentation
Ravi Bangoria ccd26741f5 perf tool: Provide an option to print perf_event_open args and return value
Perf record with verbose=2 already prints this information along with
whole lot of other traces which requires lot of scrolling. Introduce
an option to print only perf_event_open() arguments and return value.

Sample o/p:

  $ perf --debug perf-event-open=1 record -- ls > /dev/null
  ------------------------------------------------------------
  perf_event_attr:
    size                             112
    { sample_period, sample_freq }   4000
    sample_type                      IP|TID|TIME|PERIOD
    read_format                      ID
    disabled                         1
    inherit                          1
    exclude_kernel                   1
    mmap                             1
    comm                             1
    freq                             1
    enable_on_exec                   1
    task                             1
    precise_ip                       3
    sample_id_all                    1
    exclude_guest                    1
    mmap2                            1
    comm_exec                        1
    ksymbol                          1
    bpf_event                        1
  ------------------------------------------------------------
  sys_perf_event_open: pid 4308  cpu 0  group_fd -1  flags 0x8 = 4
  sys_perf_event_open: pid 4308  cpu 1  group_fd -1  flags 0x8 = 5
  sys_perf_event_open: pid 4308  cpu 2  group_fd -1  flags 0x8 = 6
  sys_perf_event_open: pid 4308  cpu 3  group_fd -1  flags 0x8 = 8
  sys_perf_event_open: pid 4308  cpu 4  group_fd -1  flags 0x8 = 9
  sys_perf_event_open: pid 4308  cpu 5  group_fd -1  flags 0x8 = 10
  sys_perf_event_open: pid 4308  cpu 6  group_fd -1  flags 0x8 = 11
  sys_perf_event_open: pid 4308  cpu 7  group_fd -1  flags 0x8 = 12
  ------------------------------------------------------------
  perf_event_attr:
    type                             1
    size                             112
    config                           0x9
    watermark                        1
    sample_id_all                    1
    bpf_event                        1
    { wakeup_events, wakeup_watermark } 1
  ------------------------------------------------------------
  sys_perf_event_open: pid -1  cpu 0  group_fd -1  flags 0x8
  sys_perf_event_open failed, error -13
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.002 MB perf.data (9 samples) ]

Committer notes:

Just like the 'verbose' variable this new 'debug_peo_args' needs to be
added to util/python.c, since we don't link the debug.o file in the
python binding, which ended up making 'perf test python' fail with:

  # perf test -v python
  18: 'import perf' in python                               :
  --- start ---
  test child forked, pid 19237
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  ImportError: /tmp/build/perf/python/perf.so: undefined symbol: debug_peo_args
  test child finished with -1
  ---- end ----
  'import perf' in python: FAILED!
  #

After adding that new variable to util/python.c:

  # perf test -v python
  18: 'import perf' in python                               :
  --- start ---
  test child forked, pid 22364
  test child finished with 0
  ---- end ----
  'import perf' in python: Ok
  #

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191108094128.28769-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-12 08:32:27 -03:00
..
android.txt
asciidoc.conf perf docs: Allow man page date to be specified 2019-09-27 09:26:14 -03:00
asciidoctor-extensions.rb
build-xed.txt
Build.txt
callchain-overhead-calculation.txt
db-export.txt perf db-export: Add brief documentation 2019-06-05 09:47:57 -03:00
examples.txt
intel-bts.txt
intel-pt.txt perf intel-pt: Add brief documentation for PEBS via Intel PT 2019-08-14 10:59:59 -03:00
itrace.txt perf tools: Add itrace option 'o' to synthesize aux-output events 2019-08-14 10:59:59 -03:00
jit-interface.txt
jitdump-specification.txt perf docs: Correct and clarify jitdump spec 2019-09-30 17:29:51 -03:00
Makefile perf tools: Fix a typo in a variable name in the Documentation Makefile 2019-08-08 15:41:10 -03:00
manpage-1.72.xsl
manpage-base.xsl
manpage-bold-literal.xsl
manpage-normal.xsl
manpage-suppress-sp.xsl
perf-annotate.txt
perf-archive.txt
perf-bench.txt
perf-buildid-cache.txt
perf-buildid-list.txt
perf-c2c.txt
perf-config.txt perf trace: Allow choosing how to augment the tracepoint arguments 2019-10-07 12:22:18 -03:00
perf-data.txt
perf-diff.txt perf diff: Report noisy for cycles diff 2019-10-11 10:57:00 -03:00
perf-evlist.txt
perf-ftrace.txt
perf-help.txt
perf-inject.txt
perf-kallsyms.txt
perf-kmem.txt
perf-kvm.txt
perf-list.txt perf list: Hide deprecated events by default 2019-10-19 15:35:01 -03:00
perf-lock.txt
perf-mem.txt
perf-probe.txt perf-probe: Add user memory access attribute support 2019-05-25 23:04:42 -04:00
perf-record.txt perf record: Add support for limit perf output file size 2019-11-07 08:30:19 -03:00
perf-report.txt perf report: Sort by sampled cycles percent per block for stdio 2019-11-07 10:14:48 -03:00
perf-sched.txt
perf-script-perl.txt
perf-script-python.txt
perf-script.txt perf script: Allow specifying event to switch off processing of other events 2019-08-15 12:24:16 -03:00
perf-stat.txt perf stat: Add --per-node agregation support 2019-11-06 15:49:39 -03:00
perf-test.txt
perf-timechart.txt
perf-top.txt perf top: Add --switch-on/--switch-off events 2019-08-15 16:03:26 -03:00
perf-trace.txt perf trace: Introduce --errno-summary 2019-10-15 13:03:49 -03:00
perf-version.txt
perf.data-directory-format.txt perf record: Put a copy of kcore into the perf.data directory 2019-11-06 15:43:05 -03:00
perf.data-file-format.txt perf.data documentation: Clarify HEADER_SAMPLE_TOPOLOGY format 2019-08-14 10:59:59 -03:00
perf.txt perf tool: Provide an option to print perf_event_open args and return value 2019-11-12 08:32:27 -03:00
perfconfig.example
tips.txt perf tools: Fix typos / broken sentences 2019-07-02 16:08:16 -03:00