perf stat: handle ENXIO error for perf_event_open
perf stat on PPC currently fails to run:
$ perf stat -- sleep 1
Error: open_counter returned with 6 (No such device or address). /bin/dmesg may provide additional information.
Fatal: Not all events could be opened.
The problem is that until 2.6.37 (behavior changed with commit b0a873e)
perf on PPC returns ENXIO when hw_perf_event_init() fails. With this
patch we get the expected behavior:
$ perf stat -v -- sleep 1
cycles event is not supported by the kernel.
stalled-cycles-frontend event is not supported by the kernel.
stalled-cycles-backend event is not supported by the kernel.
instructions event is not supported by the kernel.
branches event is not supported by the kernel.
branch-misses event is not supported by the kernel.
...
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1336490956-57145-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index e720ba7..d060568 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -462,8 +462,13 @@
list_for_each_entry(counter, &evsel_list->entries, node) {
if (create_perf_stat_counter(counter, first) < 0) {
+ /*
+ * PPC returns ENXIO for HW counters until 2.6.37
+ * (behavior changed with commit b0a873e).
+ */
if (errno == EINVAL || errno == ENOSYS ||
- errno == ENOENT || errno == EOPNOTSUPP) {
+ errno == ENOENT || errno == EOPNOTSUPP ||
+ errno == ENXIO) {
if (verbose)
ui__warning("%s event is not supported by the kernel.\n",
event_name(counter));