Messages in this thread | | | Date | Fri, 16 Nov 2018 14:35:55 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH] perf stat: Fix shadow stats for clock events |
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On Fri, Nov 16, 2018 at 09:58:43AM +0530, Ravi Bangoria wrote: > Commit 0aa802a79469 ("perf stat: Get rid of extra clock display > function") introduced scale and unit for clock events. Thus, > perf_stat__update_shadow_stats() now saves scaled values of > clock events in msecs, instead of original nsecs. But while > calculating values of shadow stats we still consider clock > event values in nsecs. This results in a wrong shadow stat > values. Ex, > > # ./perf stat -e task-clock,cycles ls > <SNIP> > 2.60 msec task-clock:u # 0.877 CPUs utilized > 2,430,564 cycles:u # 1215282.000 GHz > > Fix this by saving original nsec values for clock events in > perf_stat__update_shadow_stats(). After patch: > > # ./perf stat -e task-clock,cycles ls > <SNIP> > 3.14 msec task-clock:u # 0.839 CPUs utilized > 3,094,528 cycles:u # 0.985 GHz > > Reported-by: Anton Blanchard <anton@samba.org> > Suggested-by: Jiri Olsa <jolsa@redhat.com> > Fixes: 0aa802a79469 ("perf stat: Get rid of extra clock display function") > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
thanks, jirka
> --- > tools/perf/util/stat-shadow.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c > index f0a8cec55c47..3c22c58b3e90 100644 > --- a/tools/perf/util/stat-shadow.c > +++ b/tools/perf/util/stat-shadow.c > @@ -209,11 +209,12 @@ void perf_stat__update_shadow_stats(struct perf_evsel *counter, u64 count, > int cpu, struct runtime_stat *st) > { > int ctx = evsel_context(counter); > + u64 count_ns = count; > > count *= counter->scale; > > if (perf_evsel__is_clock(counter)) > - update_runtime_stat(st, STAT_NSECS, 0, cpu, count); > + update_runtime_stat(st, STAT_NSECS, 0, cpu, count_ns); > else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES)) > update_runtime_stat(st, STAT_CYCLES, ctx, cpu, count); > else if (perf_stat_evsel__is(counter, CYCLES_IN_TX)) > -- > 2.17.1 >
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