perf record: Force ignore_missing_thread for uid option
authorJiri Olsa <jolsa@kernel.org>
Mon, 12 Dec 2016 10:35:43 +0000 (11:35 +0100)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Thu, 15 Dec 2016 19:25:46 +0000 (16:25 -0300)
commit23dc4f1586159470aac707caae526824dd077e25
tree463a8e9d3f91cf42334bc7d4438e05c9284e2938
parenta359c17a7e1a9c99384499cf7b43d80867080789
perf record: Force ignore_missing_thread for uid option

Enable perf_evsel::ignore_missing_thread for -u option to ignore
complete failure if any of the user's processes die between its
enumeration and time we open the event.

Committer notes:

While doing a 'make -j4 allmodconfig' we sometimes get into the race:

Before:

  # perf record -u acme
  Error:
  The sys_perf_event_open() syscall returned with 3 (No such process) for event (cycles:ppp).
  /bin/dmesg may provide additional information.
  No CONFIG_PERF_EVENTS=y kernel support configured?
  #

After:

  [root@jouet ~]# perf record -u acme
  WARNING: Ignored open failure for pid 9888
  WARNING: Ignored open failure for pid 18059
  [root@jouet ~]#

Which is an improvement, with the races not preventing the remaining threads
for the specified user from being monitored, but the message probably needs
further clarification.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1481538943-21874-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/builtin-record.c