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>
23dc4f1586