From: Arnaldo Carvalho de Melo <[email protected]>
After 0161028b7c8a ("perf/core: Change the default paranoia level to 2")
'perf stat' fails for users without CAP_SYS_ADMIN, so just use
'perf_evsel__fallback()' to have the same behaviour as 'perf record',
i.e. set perf_event_attr.exclude_kernel to 1.
Now:
[acme@jouet linux]$ perf stat usleep 1
Performance counter stats for 'usleep 1':
0.352536 task-clock:u (msec) # 0.423 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
49 page-faults:u # 0.139 M/sec
309,407 cycles:u # 0.878 GHz
243,791 instructions:u # 0.79 insn per cycle
49,622 branches:u # 140.757 M/sec
3,884 branch-misses:u # 7.83% of all branches
0.000834174 seconds time elapsed
[acme@jouet linux]$
Reported-by: Ingo Molnar <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/builtin-stat.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 1f19f2f999c8..307e8a1a003c 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -528,6 +528,7 @@ static int __run_perf_stat(int argc, const char **argv)
perf_evlist__set_leader(evsel_list);
evlist__for_each(evsel_list, counter) {
+try_again:
if (create_perf_stat_counter(counter) < 0) {
/*
* PPC returns ENXIO for HW counters until 2.6.37
@@ -544,7 +545,11 @@ static int __run_perf_stat(int argc, const char **argv)
if ((counter->leader != counter) ||
!(counter->leader->nr_members > 1))
continue;
- }
+ } else if (perf_evsel__fallback(counter, errno, msg,
sizeof(msg))) {
+ if (verbose)
+ ui__warning("%s\n", msg);
+ goto try_again;
+ }
perf_evsel__open_strerror(counter, &target,
errno, msg, sizeof(msg));
--
2.5.5
