From 42ef8a78c1f49f53f29f0f3a6f9a5bcbc653233e Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 12 May 2016 16:25:18 -0300 Subject: [PATCH] perf stat: Fallback to user only counters when perf_event_paranoid > 1 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 Cc: Adrian Hunter Cc: Andy Lutomirski Cc: David Ahern Cc: Jiri Olsa Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- 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)); -- GitLab