From: Ramkumar Ramachandra Date: Mon, 30 Sep 2013 11:13:05 +0000 (+0530) Subject: perf stat: Don't print bogus data on -e cycles X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c458fe62ca31496664c1211a7906d261220b18f9;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git perf stat: Don't print bogus data on -e cycles When only the cycles event is requested: $ perf stat -e cycles dd if=/dev/zero of=/dev/null count=1000000 1000000+0 records in 1000000+0 records out 512000000 bytes (512 MB) copied, 0.26123 s, 2.0 GB/s Performance counter stats for 'dd if=/dev/zero of=/dev/null count=1000000': 911,626,453 cycles # 0.000 GHz 0.262113350 seconds time elapsed The 0.000 GHz comment in the output is totally bogus and misleading. It happens because update_shadow_stats() doesn't touch runtime_nsecs_stats; it is only written when a requested counter matches a SW_TASK_CLOCK. In our case, since we have only requested HW_CPU_CYCLES, runtime_nsecs_stats is unavailable. So, omit printing the comment altogether. Signed-off-by: Ramkumar Ramachandra Acked-by: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1380539585-23859-3-git-send-email-artagnon@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 700b47849101..ce2266c5cd52 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -997,10 +997,10 @@ static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg) } else if (perf_evsel__match(evsel, HARDWARE, HW_CPU_CYCLES)) { total = avg_stats(&runtime_nsecs_stats[cpu]); - if (total) - ratio = 1.0 * avg / total; - - fprintf(output, " # %8.3f GHz ", ratio); + if (total) { + ratio = avg / total; + fprintf(output, " # %8.3f GHz ", ratio); + } } else if (transaction_run && perf_evsel__cmp(evsel, nth_evsel(T_CYCLES_IN_TX))) { total = avg_stats(&runtime_cycles_stats[cpu]);