Commit cb5ef600 authored Jun 11, 2015 by Kan Liang Committed by Arnaldo Carvalho de Melo Jun 11, 2015

perf stat: Error out unsupported group leader immediately



perf stat ignores the unsupported event and continue to count supported
event. But if the unsupported event is group leader, perf tool will
crash. After applying this patch, the unsupported group leader will
error out immediately.

Without this patch:

  $ perf stat -x, -e '{node-prefetch-refs,cycles}' --  sleep 1
  perf: util/evsel.c:1009: get_group_fd: Assertion `!(fd == -1)' failed.
  Aborted (core dumped)

With this patch:

  $ perf stat -x, -e '{node-prefetch-refs,cycles}' --  sleep 1
  Error:
  The node-prefetch-refs event is not supported.

Commiter note: Here I got a different output, but no core dump:

  [acme@zoo linux]$ perf stat -x, -e '{node-prefetch-refs,cycles}' -- sleep 1
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument)
  for event (node-prefetch-refs).
  /bin/dmesg may provide additional information.
  No CONFIG_PERF_EVENTS=y kernel support configured?

Signed-off-by: Kan Liang <kan.liang@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Link: http://lkml.kernel.org/r/1434004360-8570-1-git-send-email-kan.liang@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 7310aed7

tools/perf/builtin-stat.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -549,6 +549,9 @@ static int __run_perf_stat(int argc, const char **argv)
		ui__warning("%s event is not supported by the kernel.\n",
		perf_evsel__name(counter));
		counter->supported = false;

		if ((counter->leader != counter) \|\|
		!(counter->leader->nr_members > 1))
		continue;
		}