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authorNamhyung Kim <namhyung@kernel.org>2020-11-27 13:14:03 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-11-27 14:31:37 -0300
commitc0ee1d5ae8c8650031badcfca6483a28c0f94f38 (patch)
tree17b7be7c2c2ee602a4964f5b96168bbe2ebecb0b /tools
parentaa50d953c169e876413bf237319e728dd41d9fdd (diff)
downloadlinux-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>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/stat-display.c5
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++) {