[PATCH v3 03/48] perf stat: Correct aggregation CPU map
Ian Rogers
irogers at google.com
Wed Dec 29 23:19:45 PST 2021
Switch the perf_cpu_map in aggr_update_shadow from
the evlist to the counter's cpu map, so the index is appropriate. This
addresses a problem where uncore counts, with a cpumap like:
$ cat /sys/devices/uncore_imc_0/cpumask
0,18
Don't aggregate counts in CPUs based on the index of those values in the
cpumap (0 and 1) but on the actual CPU (0 and 18). Thereby correcting
metric calculations in per-socket mode for counters without a full
cpumask.
On a SkylakeX with a tweaked DRAM_BW_Use metric, to remove unnecessary
scaling, this gives:
Before:
$ /perf stat --per-socket -M DRAM_BW_Use -I 1000
1.001102293 S0 1 27.01 MiB uncore_imc/cas_count_write/ # 103.00 DRAM_BW_Use
1.001102293 S0 1 30.22 MiB uncore_imc/cas_count_read/
1.001102293 S0 1 1,001,102,293 ns duration_time
1.001102293 S1 1 20.10 MiB uncore_imc/cas_count_write/ # 0.00 DRAM_BW_Use
1.001102293 S1 1 32.74 MiB uncore_imc/cas_count_read/
1.001102293 S1 0 <not counted> ns duration_time
2.003517973 S0 1 83.04 MiB uncore_imc/cas_count_write/ # 920.00 DRAM_BW_Use
2.003517973 S0 1 145.95 MiB uncore_imc/cas_count_read/
2.003517973 S0 1 1,002,415,680 ns duration_time
2.003517973 S1 1 302.45 MiB uncore_imc/cas_count_write/ # 0.00 DRAM_BW_Use
2.003517973 S1 1 290.99 MiB uncore_imc/cas_count_read/
2.003517973 S1 0 <not counted> ns duration_time
After:
$ perf stat --per-socket -M DRAM_BW_Use -I 1000
1.001080840 S0 1 24.96 MiB uncore_imc/cas_count_write/ # 54.00 DRAM_BW_Use
1.001080840 S0 1 33.64 MiB uncore_imc/cas_count_read/
1.001080840 S0 1 1,001,080,840 ns duration_time
1.001080840 S1 1 42.43 MiB uncore_imc/cas_count_write/ # 84.00 DRAM_BW_Use
1.001080840 S1 1 47.05 MiB uncore_imc/cas_count_read/
1.001080840 S1 0 <not counted> ns duration_time
Signed-off-by: Ian Rogers <irogers at google.com>
---
tools/perf/util/stat-display.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index 588601000f3f..b0fa81ffce61 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -526,7 +526,7 @@ static void aggr_update_shadow(struct perf_stat_config *config,
evlist__for_each_entry(evlist, counter) {
val = 0;
for (cpu = 0; cpu < evsel__nr_cpus(counter); cpu++) {
- s2 = config->aggr_get_id(config, evlist->core.cpus, cpu);
+ s2 = config->aggr_get_id(config, evsel__cpus(counter), cpu);
if (!cpu_map__compare_aggr_cpu_id(s2, id))
continue;
val += perf_counts(counter->counts, cpu, 0)->val;
--
2.34.1.448.ga2b2bfdf31-goog
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