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| author | Namhyung Kim <namhyung@kernel.org> | 2020-11-27 13:14:03 +0900 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-11-27 14:31:37 -0300 |
| commit | c0ee1d5ae8c8650031badcfca6483a28c0f94f38 (patch) | |
| tree | 17b7be7c2c2ee602a4964f5b96168bbe2ebecb0b | |
| parent | aa50d953c169e876413bf237319e728dd41d9fdd (diff) | |
| download | linux-c0ee1d5ae8c8650031badcfca6483a28c0f94f38.tar.bz2 | |
perf stat: Use proper cpu for shadow stats
Currently perf stat shows some metrics (like IPC) for defined events.
But when no aggregation mode is used (-A option), it shows incorrect
values since it used a value from a different cpu.
Before:
$ perf stat -aA -e cycles,instructions sleep 1
Performance counter stats for 'system wide':
CPU0 116,057,380 cycles
CPU1 86,084,722 cycles
CPU2 99,423,125 cycles
CPU3 98,272,994 cycles
CPU0 53,369,217 instructions # 0.46 insn per cycle
CPU1 33,378,058 instructions # 0.29 insn per cycle
CPU2 58,150,086 instructions # 0.50 insn per cycle
CPU3 40,029,703 instructions # 0.34 insn per cycle
1.001816971 seconds time elapsed
So the IPC for CPU1 should be 0.38 (= 33,378,058 / 86,084,722)
but it was 0.29 (= 33,378,058 / 116,057,380) and so on.
After:
$ perf stat -aA -e cycles,instructions sleep 1
Performance counter stats for 'system wide':
CPU0 109,621,384 cycles
CPU1 159,026,454 cycles
CPU2 99,460,366 cycles
CPU3 124,144,142 cycles
CPU0 44,396,706 instructions # 0.41 insn per cycle
CPU1 120,195,425 instructions # 0.76 insn per cycle
CPU2 44,763,978 instructions # 0.45 insn per cycle
CPU3 69,049,079 instructions # 0.56 insn per cycle
1.001910444 seconds time elapsed
Fixes: 44d49a600259 ("perf stat: Support metrics in --per-core/socket mode")
Reported-by: Sam Xi <xyzsam@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201127041404.390276-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/stat-display.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index 4b57c0c07632..a963b5b8eb72 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -324,13 +324,10 @@ static int first_shadow_cpu(struct perf_stat_config *config, struct evlist *evlist = evsel->evlist; int i; - if (!config->aggr_get_id) - return 0; - if (config->aggr_mode == AGGR_NONE) return id; - if (config->aggr_mode == AGGR_GLOBAL) + if (!config->aggr_get_id) return 0; for (i = 0; i < evsel__nr_cpus(evsel); i++) { |