From 51fd2df1e882a3c2a3f4b6c9ff243a93c9046dba Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 3 Feb 2016 08:43:56 +0100 Subject: [PATCH] perf stat: Fix interval output values We broke interval data displays with commit: 3f416f22d1e2 ("perf stat: Do not clean event's private stats") This commit removed stats cleaning, which is important for '-r' option to carry counters data over the whole run. But it's necessary to clean it for interval mode, otherwise the displayed value is avg of all previous values. Before: $ perf stat -e cycles -a -I 1000 record # time counts unit events 1.000240796 75,216,287 cycles 2.000512791 107,823,524 cycles $ perf stat report # time counts unit events 1.000240796 75,216,287 cycles 2.000512791 91,519,906 cycles Now: $ perf stat report # time counts unit events 1.000240796 75,216,287 cycles 2.000512791 107,823,524 cycles Notice the second value being bigger (91,.. < 107,..). This could be easily verified by using perf script which displays raw stat data: $ perf script CPU THREAD VAL ENA RUN TIME EVENT 0 -1 23855779 1000209530 1000209530 1000240796 cycles 1 -1 33340397 1000224964 1000224964 1000240796 cycles 2 -1 15835415 1000226695 1000226695 1000240796 cycles 3 -1 2184696 1000228245 1000228245 1000240796 cycles 0 -1 97014312 2000514533 2000514533 2000512791 cycles 1 -1 46121497 2000543795 2000543795 2000512791 cycles 2 -1 32269530 2000543566 2000543566 2000512791 cycles 3 -1 7634472 2000544108 2000544108 2000512791 cycles The sum of the first 4 values is the first interval aggregated value: 23855779 + 33340397 + 15835415 + 2184696 = 75,216,287 The sum of the second 4 values minus first value is the second interval aggregated value: 97014312 + 46121497 + 32269530 + 7634472 - 75216287 = 107,823,524 Signed-off-by: Jiri Olsa Cc: Andi Kleen Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1454485436-20639-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/stat.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c index 2b58edccd56f..afb0c45eba34 100644 --- a/tools/perf/util/stat.c +++ b/tools/perf/util/stat.c @@ -311,6 +311,16 @@ int perf_stat_process_counter(struct perf_stat_config *config, aggr->val = aggr->ena = aggr->run = 0; + /* + * We calculate counter's data every interval, + * and the display code shows ps->res_stats + * avg value. We need to zero the stats for + * interval mode, otherwise overall avg running + * averages will be shown for each interval. + */ + if (config->interval) + init_stats(ps->res_stats); + if (counter->per_pkg) zero_per_pkg(counter); -- 2.30.2