From: Namhyung Kim namhyung@kernel.org
[ Upstream commit dd15480a3d67b9cf04a1f6f5d60f1c0dc018e22f ]
The current display code for perf stat iterates given cpus and build the aggr map to collect the event data for the aggregation mode.
But uncore events have their own cpu maps and it won't guarantee that it'd match to the aggr map. For example, per-package uncore events would generate a single value for each socket. When user asks per-core aggregation mode, the output would contain 0 values for other cores.
Thus it needs to check the uncore PMU's cpumask and if it matches to the current aggregation id.
Before: $ sudo ./perf stat -a --per-core -e power/energy-pkg/ sleep 1
Performance counter stats for 'system wide':
S0-D0-C0 1 3.73 Joules power/energy-pkg/ S0-D0-C1 0 <not counted> Joules power/energy-pkg/ S0-D0-C2 0 <not counted> Joules power/energy-pkg/ S0-D0-C3 0 <not counted> Joules power/energy-pkg/
1.001404046 seconds time elapsed
Some events weren't counted. Try disabling the NMI watchdog: echo 0 > /proc/sys/kernel/nmi_watchdog perf stat ... echo 1 > /proc/sys/kernel/nmi_watchdog
The core 1, 2 and 3 should not be printed because the event is handled in a cpu in the core 0 only. With this change, the output becomes like below.
After: $ sudo ./perf stat -a --per-core -e power/energy-pkg/ sleep 1
Performance counter stats for 'system wide':
S0-D0-C0 1 2.09 Joules power/energy-pkg/
Fixes: b897613510890d6e ("perf stat: Update event skip condition for system-wide per-thread mode and merged uncore and hybrid events") Signed-off-by: Namhyung Kim namhyung@kernel.org Tested-by: Ian Rogers irogers@google.com Acked-by: Ian Rogers irogers@google.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Athira Rajeev atrajeev@linux.vnet.ibm.com Cc: Ingo Molnar mingo@kernel.org Cc: Jiri Olsa jolsa@kernel.org Cc: Michael Petlan mpetlan@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: https://lore.kernel.org/r/20230125192431.2929677-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/stat-display.c | 51 ++++++++++++++++++++++++++++++---- 1 file changed, 46 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index 8bd8b0142630c..1b5cb20efd237 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -787,6 +787,51 @@ static void uniquify_counter(struct perf_stat_config *config, struct evsel *coun uniquify_event_name(counter); }
+/** + * should_skip_zero_count() - Check if the event should print 0 values. + * @config: The perf stat configuration (including aggregation mode). + * @counter: The evsel with its associated cpumap. + * @id: The aggregation id that is being queried. + * + * Due to mismatch between the event cpumap or thread-map and the + * aggregation mode, sometimes it'd iterate the counter with the map + * which does not contain any values. + * + * For example, uncore events have dedicated CPUs to manage them, + * result for other CPUs should be zero and skipped. + * + * Return: %true if the value should NOT be printed, %false if the value + * needs to be printed like "<not counted>" or "<not supported>". + */ +static bool should_skip_zero_counter(struct perf_stat_config *config, + struct evsel *counter, + const struct aggr_cpu_id *id) +{ + struct perf_cpu cpu; + int idx; + + /* + * Skip value 0 when enabling --per-thread globally, + * otherwise it will have too many 0 output. + */ + if (config->aggr_mode == AGGR_THREAD && config->system_wide) + return true; + /* + * Skip value 0 when it's an uncore event and the given aggr id + * does not belong to the PMU cpumask. + */ + if (!counter->pmu || !counter->pmu->is_uncore) + return false; + + perf_cpu_map__for_each_cpu(cpu, idx, counter->pmu->cpus) { + struct aggr_cpu_id own_id = config->aggr_get_id(config, cpu); + + if (aggr_cpu_id__equal(id, &own_id)) + return false; + } + return true; +} + static void print_counter_aggrdata(struct perf_stat_config *config, struct evsel *counter, int s, struct outstate *os) @@ -814,11 +859,7 @@ static void print_counter_aggrdata(struct perf_stat_config *config, ena = aggr->counts.ena; run = aggr->counts.run;
- /* - * Skip value 0 when enabling --per-thread globally, otherwise it will - * have too many 0 output. - */ - if (val == 0 && config->aggr_mode == AGGR_THREAD && config->system_wide) + if (val == 0 && should_skip_zero_counter(config, counter, &id)) return;
if (!metric_only) {