linux-stable.git/tools/perf/Documentation, branch v5.12.2

perf tools: Fix documentation of verbose options

2021-03-06T19:54:26+00:00

Option doesn't take a value, make sure the man pages agree. For example:

  $ perf evlist --verbose=1
   Error: option `verbose' takes no value

Signed-off-by: Ian Rogers 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20210226183145.1878782-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add documentation for tracing virtual machines

2021-02-18T19:15:55+00:00

Add documentation to the perf-intel-pt man page for tracing virtual
machines.

Signed-off-by: Adrian Hunter 
Acked-by: Andi Kleen 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210218095801.19576-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add PSB events

2021-02-18T19:04:10+00:00

Emitting a PSB+ can cause a CPU a slight delay. When doing timing analysis
of code with Intel PT, it is useful to know if a timing bubble was caused
by Intel PT or not. Add reporting of PSB events via perf script. PSB
events are printed with the existing itrace 'p' option which also prints
power and frequency changes. The PSB event contains the trace offset at
which the PSB occurs, to allow easy reference back to the PSB+ packets.

The PSB event timestamp is always the timestamp from the PSB+ TSC
packet, and the ip is always the address from the PSB+ FUP packet.

The code changes are non-trivial because the decoder must walk to the
PSB+ FUP address before outputting the PSB event.

Example:

  $ perf record -e intel_pt/cyc,psb_period=0/u uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.046 MB perf.data ]
  $ perf script --itrace=p --ns
     perf 17981 [006] 25617.510820383:  psb:  psb offs: 0                               0 [unknown] ([unknown])
     perf 17981 [006] 25617.510820383:  cbr:  cbr: 42 freq: 4219 MHz (156%)             0 [unknown] ([unknown])
    uname 17981 [006] 25617.510889753:  psb:  psb offs: 0xb50                7f78c12a212e __GI___tunables_init+0xee (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510899162:  psb:  psb offs: 0x12d0               7f78c128af1c dl_main+0x93c (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510939242:  psb:  psb offs: 0x1a50               7f78c128eefc _dl_map_object_from_fd+0x13c (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510981274:  psb:  psb offs: 0x21c8               7f78c1296307 _dl_relocate_object+0x927 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510993034:  psb:  psb offs: 0x2948               7f78c12940e4 _dl_lookup_symbol_x+0x14 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511003871:  psb:  psb offs: 0x30c8               7f78c12937b3 do_lookup_x+0x2f3 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511019854:  psb:  psb offs: 0x3850               7f78c1295eed _dl_relocate_object+0x50d (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511029015:  psb:  psb offs: 0x4390               7f78c12a855a strcmp+0xf6a (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511064876:  psb:  psb offs: 0x4b10                          0 [unknown] ([unknown])
    uname 17981 [006] 25617.511080762:  psb:  psb offs: 0x5290               7f78c11db53d _dl_addr+0x13d (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511086035:  psb:  psb offs: 0x5a08               7f78c11db538 _dl_addr+0x138 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511091381:  psb:  psb offs: 0x6190               7f78c11db534 _dl_addr+0x134 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511096681:  psb:  psb offs: 0x6910               7f78c11db4c3 _dl_addr+0xc3 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511119520:  psb:  psb offs: 0x7090               7f78c10ada5e _nl_intern_locale_data+0x12e (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511126584:  psb:  psb offs: 0x7818               7f78c10ada50 _nl_intern_locale_data+0x120 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511132775:  psb:  psb offs: 0x8358               7f78c10c20c0 getenv+0xa0 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511134598:  psb:  psb offs: 0x8ad0               7f78c10ada09 _nl_intern_locale_data+0xd9 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511135685:  psb:  psb offs: 0x9258               7f78c10ada50 _nl_intern_locale_data+0x120 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511138322:  psb:  psb offs: 0x99d0               7f78c11fffd9 __strncmp_avx2+0x39 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511158907:  psb:  psb offs: 0xa150                          0 [unknown] ([unknown])

Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210205175350.23817-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Replace lkml.org links with lore

2021-02-11T15:54:27+00:00

As started by commit 05a5f51ca566 ("Documentation: Replace lkml.org
links with lore"), replace lkml.org links with lore to better use a
single source that's more likely to stay available long-term.

Signed-off-by: Kees Kook 
Acked-by: Namhyung Kim 
Acked-by: Peter Zijlstra 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Joe Perches 
Cc: Kees Kook 
Cc: Mark Rutland 
Link: http://lore.kernel.org/lkml/20210210234220.2401035-1-keescook@chromium.org
Signed-off-by: Arnaldo Carvalho de Melo

perf daemon: Add examples to man page

2021-02-11T13:19:52+00:00

Add usage examples to the man page.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210208200908.1019149-19-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf daemon: Add 'ping' command

2021-02-11T13:19:52+00:00

Add a 'ping' command to verify that the 'perf record' session is up and
operational.

It's used in the following patches via test code to make sure 'perf
record' is ready to receive signals.

Example:

  # cat ~/.perfconfig
  [daemon]
  base=/opt/perfdata

  [session-cycles]
  run = -m 10M -e cycles --overwrite --switch-output -a

  [session-sched]
  run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

  # perf daemon start

Ping all sessions:

  # perf daemon ping
  OK   cycles
  OK   sched

Ping specific session:

  # perf daemon ping --session sched
  OK   sched

Committer notes:

Fixed up bug pointed by clang:

Buggy:

  if (!pollfd.revents & POLLIN)

Correct code:

  if (!(pollfd.revents & POLLIN))

clang warning:

  builtin-daemon.c:560:6: error: logical not is only applied to the left hand side of this bitwise operator [-Werror,-Wlogical-not-parentheses]
          if (!pollfd.revents & POLLIN) {
              ^               ~
  builtin-daemon.c:560:6: note: add parentheses after the '!' to evaluate the bitwise operator first

Also use designated initialized with pollfd, i.e.:

  struct pollfd pollfd = { .events = POLLIN, };

Instead of:

  struct pollfd pollfd = { 0, };

To get past:

    builtin-daemon.c:510:30: error: missing field 'events' initializer [-Werror,-Wmissing-field-initializers]
            struct pollfd pollfd = { 0, };
                                        ^
    1 error generated.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210208200908.1019149-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf daemon: Set control fifo for session

2021-02-11T13:19:52+00:00

Setup control fifos for session and add --control option to session
arguments.

Example:

  # cat ~/.perfconfig
  [daemon]
  base=/opt/perfdata

  [session-cycles]
  run = -m 10M -e cycles --overwrite --switch-output -a

  [session-sched]
  run = -m 20M -e sched:* --overwrite --switch-output -a

Starting the daemon:

  # perf daemon start

Use can list control fifos with (control and ack files):

  # perf daemon -v
  [776459:daemon] base: /opt/perfdata
    output:  /opt/perfdata/output
    lock:    /opt/perfdata/lock
  [776460:cycles] perf record -m 20M -e cycles --overwrite --switch-output -a
    base:    /opt/perfdata/session-cycles
    output:  /opt/perfdata/session-cycles/output
    control: /opt/perfdata/session-cycles/control
    ack:     /opt/perfdata/session-cycles/ack
  [776461:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
    base:    /opt/perfdata/session-sched
    output:  /opt/perfdata/session-sched/output
    control: /opt/perfdata/session-sched/control
    ack:     /opt/perfdata/session-sched/ack

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210208200908.1019149-15-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf daemon: Allow only one daemon over base directory

2021-02-11T13:16:56+00:00

Add 'lock' file under daemon base and flock it, so only one perf daemon
can run on top of it.

Each daemon tries to create and lock BASE/lock file, if it's successful
we are sure we're the only daemon running over the BASE.

Once daemon is finished, file descriptor to lock file is closed and lock
is released.

Example:

  # cat ~/.perfconfig
  [daemon]
  base=/opt/perfdata

  [session-cycles]
  run = -m 10M -e cycles --overwrite --switch-output -a

  [session-sched]
  run = -m 20M -e sched:* --overwrite --switch-output -a

Starting the daemon:

  # perf daemon start

And try once more:

  # perf daemon start
  failed: another perf daemon (pid 775594) owns /opt/perfdata

will end up with an error, because there's already one running
on top of /opt/perfdata.

Committer notes:

Provide lockf(F_TLOCK) when not available, i.e. transform:

  lockf(fd, F_TLOCK, 0);

into:

  flock(fd, LOCK_EX | LOCK_NB);

Which should be equivalent.

Noticed when cross building to some odd Android NDK.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210208200908.1019149-14-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf daemon: Add 'stop' command

2021-02-11T13:02:54+00:00

Add 'perf daemon stop' command to stop daemon process and all running
sessions.

Example:

  # cat ~/.perfconfig
  [daemon]
  base=/opt/perfdata

  [session-cycles]
  run = -m 10M -e cycles --overwrite --switch-output -a

  [session-sched]
  run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

  # perf daemon start

Stop the daemon

  # perf daemon stop

Daemon is not running, nothing to connect to:

  # perf daemon
  connect error: Connection refused

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210208200908.1019149-13-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf daemon: Add 'signal' command

2021-02-11T13:02:54+00:00

Allow the 'perf daemon' to send SIGUSR2 to all running sessions or just
to a specific session.

Example:

  # cat ~/.perfconfig
  [daemon]
  base=/opt/perfdata

  [session-cycles]
  run = -m 10M -e cycles --overwrite --switch-output -a

  [session-sched]
  run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

  # perf daemon start

Send signal to all running sessions:

  # perf daemon signal
  signal 12 sent to session 'cycles [773738]'
  signal 12 sent to session 'sched [773739]'

Or to specific one:

  # perf daemon signal --session sched
  signal 12 sent to session 'sched [773739]'

And verify signals were delivered and perf.data dumped:

  # cat /opt/perfdata/session-cycles/output
  rounding mmap pages size to 32M (8192 pages)
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2021010220382490 ]

  # car /opt/perfdata/session-sched/output
  rounding mmap pages size to 32M (8192 pages)
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2021010220382489 ]
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2021010220393745 ]

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20210208200908.1019149-12-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo