perf stat: Fix compatibility behavior
Instead of failing on an unknown event, when new perf stat is run on
older kernels:
$ ./perf stat true
Error: open_counter returned with 22 (Invalid argument). /bin/dmesg
may provide additional information.
Fatal: Not all events could be opened.
Just ignore EINVAL and ENOSYS, we'll print the results as not counted:
Performance counter stats for 'true':
0.239483 task-clock # 0.493 CPUs utilized
0 context-switches # 0.000 M/sec
0 CPU-migrations # 0.000 M/sec
86 page-faults # 0.359 M/sec
704,766 cycles # 2.943 GHz
<not counted> stalled-cycles
381,961 instructions # 0.54 insns per cycle
69,626 branches # 290.735 M/sec
4,594 branch-misses # 6.60% of all branches
0.000485883 seconds time elapsed
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-7y40wib8n1eqio5hjpn3dsrm@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 5658a77..da77077 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -372,7 +372,10 @@
list_for_each_entry(counter, &evsel_list->entries, node) {
if (create_perf_stat_counter(counter) < 0) {
- if (errno == -EPERM || errno == -EACCES) {
+ if (errno == EINVAL || errno == ENOSYS)
+ continue;
+
+ if (errno == EPERM || errno == EACCES) {
error("You may not have permission to collect %sstats.\n"
"\t Consider tweaking"
" /proc/sys/kernel/perf_event_paranoid or running as root.",