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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>
hifive-unleashed-5.1
David Ahern 2012-05-08 09:29:16 -06:00 committed by Arnaldo Carvalho de Melo
parent 09c0211c0b
commit 20d23aaa31
1 changed files with 6 additions and 1 deletions
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7
tools/perf/builtin-stat.c
View File

@ -488,8 +488,13 @@ static int run_perf_stat(int argc __used, const char **argv)
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));