+++ /dev/null
-From d7f988d8e1aa5c4f7691c2dbb580db3188cf6297 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Wed, 4 Sep 2019 15:17:37 +0530
-Subject: perf stat: Reset previous counts on repeat with interval
-
-From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
-
-[ Upstream commit b63fd11cced17fcb8e133def29001b0f6aaa5e06 ]
-
-When using 'perf stat' with repeat and interval option, it shows wrong
-values for events.
-
-The wrong values will be shown for the first interval on the second and
-subsequent repetitions.
-
-Without the fix:
-
- # perf stat -r 3 -I 2000 -e faults -e sched:sched_switch -a sleep 5
-
- 2.000282489 53 faults
- 2.000282489 513 sched:sched_switch
- 4.005478208 3,721 faults
- 4.005478208 2,666 sched:sched_switch
- 5.025470933 395 faults
- 5.025470933 1,307 sched:sched_switch
- 2.009602825 1,84,46,74,40,73,70,95,47,520 faults <------
- 2.009602825 1,84,46,74,40,73,70,95,49,568 sched:sched_switch <------
- 4.019612206 4,730 faults
- 4.019612206 2,746 sched:sched_switch
- 5.039615484 3,953 faults
- 5.039615484 1,496 sched:sched_switch
- 2.000274620 1,84,46,74,40,73,70,95,47,520 faults <------
- 2.000274620 1,84,46,74,40,73,70,95,47,520 sched:sched_switch <------
- 4.000480342 4,282 faults
- 4.000480342 2,303 sched:sched_switch
- 5.000916811 1,322 faults
- 5.000916811 1,064 sched:sched_switch
- #
-
-prev_raw_counts is allocated when using intervals. This is used when
-calculating the difference in the counts of events when using interval.
-
-The current counts are stored in prev_raw_counts to calculate the
-differences in the next iteration.
-
-On the first interval of the second and subsequent repetitions,
-prev_raw_counts would be the values stored in the last interval of the
-previous repetitions, while the current counts will only be for the
-first interval of the current repetition.
-
-Hence there is a possibility of events showing up as big number.
-
-Fix this by resetting prev_raw_counts whenever perf stat repeats the
-command.
-
-With the fix:
-
- # perf stat -r 3 -I 2000 -e faults -e sched:sched_switch -a sleep 5
-
- 2.019349347 2,597 faults
- 2.019349347 2,753 sched:sched_switch
- 4.019577372 3,098 faults
- 4.019577372 2,532 sched:sched_switch
- 5.019415481 1,879 faults
- 5.019415481 1,356 sched:sched_switch
- 2.000178813 8,468 faults
- 2.000178813 2,254 sched:sched_switch
- 4.000404621 7,440 faults
- 4.000404621 1,266 sched:sched_switch
- 5.040196079 2,458 faults
- 5.040196079 556 sched:sched_switch
- 2.000191939 6,870 faults
- 2.000191939 1,170 sched:sched_switch
- 4.000414103 541 faults
- 4.000414103 902 sched:sched_switch
- 5.000809863 450 faults
- 5.000809863 364 sched:sched_switch
- #
-
-Committer notes:
-
-This was broken since the cset introducing the --interval feature, i.e.
---repeat + --interval wasn't tested at that point, add the Fixes tag so
-that automatic scripts can pick this up.
-
-Fixes: 13370a9b5bb8 ("perf stat: Add interval printing")
-Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
-Acked-by: Jiri Olsa <jolsa@kernel.org>
-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
-Cc: Namhyung Kim <namhyung@kernel.org>
-Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
-Cc: Stephane Eranian <eranian@google.com>
-Cc: stable@vger.kernel.org # v3.9+
-Link: http://lore.kernel.org/lkml/20190904094738.9558-2-srikar@linux.vnet.ibm.com
-[ Fixed up conflicts with libperf, i.e. some perf_{evsel,evlist} lost the 'perf' prefix ]
-Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- tools/perf/builtin-stat.c | 3 +++
- tools/perf/util/stat.c | 17 +++++++++++++++++
- tools/perf/util/stat.h | 1 +
- 3 files changed, 21 insertions(+)
-
-diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
-index 65a6922db7223..e80d47fdda3e1 100644
---- a/tools/perf/builtin-stat.c
-+++ b/tools/perf/builtin-stat.c
-@@ -1415,6 +1415,9 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
- fprintf(output, "[ perf stat: executing run #%d ... ]\n",
- run_idx + 1);
-
-+ if (run_idx != 0)
-+ perf_evlist__reset_prev_raw_counts(evsel_list);
-+
- status = run_perf_stat(argc, argv);
- if (forever && status != -1 && !interval) {
- print_counters(NULL, argc, argv);
-diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
-index 6ce624cb70012..a252714700d3c 100644
---- a/tools/perf/util/stat.c
-+++ b/tools/perf/util/stat.c
-@@ -140,6 +140,15 @@ void perf_evsel__free_prev_raw_counts(struct perf_evsel *evsel)
- evsel->prev_raw_counts = NULL;
- }
-
-+static void perf_evsel__reset_prev_raw_counts(struct perf_evsel *evsel)
-+{
-+ if (evsel->prev_raw_counts) {
-+ evsel->prev_raw_counts->aggr.val = 0;
-+ evsel->prev_raw_counts->aggr.ena = 0;
-+ evsel->prev_raw_counts->aggr.run = 0;
-+ }
-+}
-+
- int perf_evsel__alloc_stats(struct perf_evsel *evsel, bool alloc_raw)
- {
- int ncpus = perf_evsel__nr_cpus(evsel);
-@@ -190,6 +199,14 @@ void perf_evlist__reset_stats(struct perf_evlist *evlist)
- }
- }
-
-+void perf_evlist__reset_prev_raw_counts(struct perf_evlist *evlist)
-+{
-+ struct perf_evsel *evsel;
-+
-+ evlist__for_each_entry(evlist, evsel)
-+ perf_evsel__reset_prev_raw_counts(evsel);
-+}
-+
- static void zero_per_pkg(struct perf_evsel *counter)
- {
- if (counter->per_pkg_mask)
-diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
-index da1d11c4f8c19..5d6631207a506 100644
---- a/tools/perf/util/stat.h
-+++ b/tools/perf/util/stat.h
-@@ -87,6 +87,7 @@ int perf_evsel__alloc_stats(struct perf_evsel *evsel, bool alloc_raw);
- int perf_evlist__alloc_stats(struct perf_evlist *evlist, bool alloc_raw);
- void perf_evlist__free_stats(struct perf_evlist *evlist);
- void perf_evlist__reset_stats(struct perf_evlist *evlist);
-+void perf_evlist__reset_prev_raw_counts(struct perf_evlist *evlist);
-
- int perf_stat_process_counter(struct perf_stat_config *config,
- struct perf_evsel *counter);
---
-2.20.1
-
projects / thirdparty / kernel / stable-queue.git / commitdiff
