From 493be70ac3cdf016d3b608a6c3c0048242a68925 Mon Sep 17 00:00:00 2001 From: Jin Yao Date: Thu, 10 Jun 2021 11:45:57 +0800 Subject: [PATCH] perf stat: Disable the NMI watchdog message on hybrid If we run a single workload that only runs on big core, there is always a ugly message about disabling the NMI watchdog because the atom is not counted. Before: # ./perf stat true Performance counter stats for 'true': 0.43 msec task-clock # 0.396 CPUs utilized 0 context-switches # 0.000 /sec 0 cpu-migrations # 0.000 /sec 45 page-faults # 103.918 K/sec 639,634 cpu_core/cycles/ # 1.477 G/sec cpu_atom/cycles/ (0.00%) 643,498 cpu_core/instructions/ # 1.486 G/sec cpu_atom/instructions/ (0.00%) 123,715 cpu_core/branches/ # 285.694 M/sec cpu_atom/branches/ (0.00%) 4,094 cpu_core/branch-misses/ # 9.454 M/sec cpu_atom/branch-misses/ (0.00%) 0.001092407 seconds time elapsed 0.001144000 seconds user 0.000000000 seconds sys 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 # ./perf stat -e '{cpu_atom/cycles/,msr/tsc/}' true Performance counter stats for 'true': cpu_atom/cycles/ (0.00%) msr/tsc/ (0.00%) 0.001904106 seconds time elapsed 0.001947000 seconds user 0.000000000 seconds sys 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 events in group usually have to be from the same PMU. Try reorganizing the group. Now we disable the NMI watchdog message on hybrid, otherwise there are too many false positives. After: # ./perf stat true Performance counter stats for 'true': 0.79 msec task-clock # 0.419 CPUs utilized 0 context-switches # 0.000 /sec 0 cpu-migrations # 0.000 /sec 48 page-faults # 60.889 K/sec 777,692 cpu_core/cycles/ # 986.519 M/sec cpu_atom/cycles/ (0.00%) 669,147 cpu_core/instructions/ # 848.828 M/sec cpu_atom/instructions/ (0.00%) 128,635 cpu_core/branches/ # 163.176 M/sec cpu_atom/branches/ (0.00%) 4,089 cpu_core/branch-misses/ # 5.187 M/sec cpu_atom/branch-misses/ (0.00%) 0.001880649 seconds time elapsed 0.001935000 seconds user 0.000000000 seconds sys # ./perf stat -e '{cpu_atom/cycles/,msr/tsc/}' true Performance counter stats for 'true': cpu_atom/cycles/ (0.00%) msr/tsc/ (0.00%) 0.000963319 seconds time elapsed 0.000999000 seconds user 0.000000000 seconds sys Signed-off-by: Jin Yao Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jin Yao Cc: Kan Liang Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20210610034557.29766-1-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/stat-display.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index c588a6b7a8db..83a2bc02df15 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -19,6 +19,7 @@ #include "util.h" #include "iostat.h" #include "pmu-hybrid.h" +#include "evlist-hybrid.h" #define CNTR_NOT_SUPPORTED "" #define CNTR_NOT_COUNTED "" @@ -465,9 +466,11 @@ static void printout(struct perf_stat_config *config, struct aggr_cpu_id id, int config->csv_sep); if (counter->supported) { - config->print_free_counters_hint = 1; - if (is_mixed_hw_group(counter)) - config->print_mixed_hw_group_error = 1; + if (!evlist__has_hybrid(counter->evlist)) { + config->print_free_counters_hint = 1; + if (is_mixed_hw_group(counter)) + config->print_mixed_hw_group_error = 1; + } } fprintf(config->output, "%-*s%s", -- GitLab