perf stat: Failure with "Operation not supported"
perf stat is failing on PowerPC: Error: open_counter returned with 95 (Operation not supported). /bin/dmesg may provide additional information. Fatal: Not all events could be opened. commit 370faf1d (perf stat: Fail softly on unsupported events) added a check for failure returning ENOENT, but the POWER backend returns EOPNOTSUPP. It looks like alpha, blackfin and mips do the same. With the patch applied, things work as expected: Performance counter stats for '/bin/true': 0.362176 task-clock # 0.623 CPUs utilized 0 context-switches # 0.000 M/sec 0 CPU-migrations # 0.000 M/sec 28 page-faults # 0.077 M/sec 1,677,020 cycles # 4.630 GHz <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 431,220 instructions # 0.26 insns per cycle 101,889 branches # 281.325 M/sec 4,145 branch-misses # 4.07% of all branches 0.000581361 seconds time elapsed Cc: <stable@kernel.org> # 3.0+ Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111202093833.5fef7226@krytenSigned-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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