This does follow two changes: 1) Select appropriate unit between K/M/G. 2) Use 'cpu-sec' instead of 'sec' to state this is not the wall-time.
$ sudo ./perf stat -a -- sleep 1 Before: Unit 'M' is selected even the number is very small. Performance counter stats for 'system wide': 4,003.06 msec cpu-clock # 3.998 CPUs utilized 16,179 context-switches # 0.004 M/sec 161 cpu-migrations # 0.040 K/sec 4,699 page-faults # 0.001 M/sec 6,135,801,925 cycles # 1.533 GHz (83.21%) 5,783,308,491 stalled-cycles-frontend # 94.26% frontend cycles idle (83.21%) 4,543,694,050 stalled-cycles-backend # 74.05% backend cycles idle (66.49%) 4,720,130,587 instructions # 0.77 insn per cycle # 1.23 stalled cycles per insn (83.28%) 753,848,078 branches # 188.318 M/sec (83.61%) 37,457,747 branch-misses # 4.97% of all branches (83.48%) 1.001283725 seconds time elapsed After: $ sudo ./perf stat -a -- sleep 2 Performance counter stats for 'system wide': 8,003.20 msec cpu-clock # 3.998 CPUs utilized 9,768 context-switches # 1.221 K/cpu-sec 164 cpu-migrations # 20.492 /cpu-sec 74,146 page-faults # 9.265 K/cpu-sec 19,008,796,806 cycles # 2.375 GHz (83.21%) 14,789,443,853 stalled-cycles-frontend # 77.80% frontend cycles idle (83.29%) 11,867,812,064 stalled-cycles-backend # 62.43% backend cycles idle (66.80%) 9,898,252,603 instructions # 0.52 insn per cycle # 1.49 stalled cycles per insn (83.41%) 2,063,251,998 branches # 257.803 M/cpu-sec (83.41%) 86,941,704 branch-misses # 4.21% of all branches (83.30%) 2.001743706 seconds time elapsed Signed-off-by: Changbin Du <changbin...@gmail.com> --- tools/perf/util/stat-shadow.c | 13 +++++-------- tools/perf/util/units.c | 22 ++++++++++++++++++++++ tools/perf/util/units.h | 1 + 3 files changed, 28 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c index 6ccf21a72f06..786b5ef512d8 100644 --- a/tools/perf/util/stat-shadow.c +++ b/tools/perf/util/stat-shadow.c @@ -9,6 +9,7 @@ #include "expr.h" #include "metricgroup.h" #include "cgroup.h" +#include "units.h" #include <linux/zalloc.h> /* @@ -1270,18 +1271,14 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config, generic_metric(config, evsel->metric_expr, evsel->metric_events, NULL, evsel->name, evsel->metric_name, NULL, 1, cpu, out, st); } else if (runtime_stat_n(st, STAT_NSECS, cpu, &rsd) != 0) { - char unit = 'M'; + char unit = ' '; char unit_buf[10]; total = runtime_stat_avg(st, STAT_NSECS, cpu, &rsd); - if (total) - ratio = 1000.0 * avg / total; - if (ratio < 0.001) { - ratio *= 1000; - unit = 'K'; - } - snprintf(unit_buf, sizeof(unit_buf), "%c/sec", unit); + ratio = convert_unit_double(1000000000.0 * avg / total, &unit); + + snprintf(unit_buf, sizeof(unit_buf), "%c/cpu-sec", unit); print_metric(config, ctxp, NULL, "%8.3f", unit_buf, ratio); } else if (perf_stat_evsel__is(evsel, SMI_NUM)) { print_smi_cost(config, cpu, out, st, &rsd); diff --git a/tools/perf/util/units.c b/tools/perf/util/units.c index a46762aec4c9..ac13b5ecde31 100644 --- a/tools/perf/util/units.c +++ b/tools/perf/util/units.c @@ -55,6 +55,28 @@ unsigned long convert_unit(unsigned long value, char *unit) return value; } +double convert_unit_double(double value, char *unit) +{ + *unit = ' '; + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'K'; + } + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'M'; + } + + if (value > 1000.0) { + value /= 1000.0; + *unit = 'G'; + } + + return value; +} + int unit_number__scnprintf(char *buf, size_t size, u64 n) { char unit[4] = "BKMG"; diff --git a/tools/perf/util/units.h b/tools/perf/util/units.h index 99263b6a23f7..b3ace67ac16f 100644 --- a/tools/perf/util/units.h +++ b/tools/perf/util/units.h @@ -13,6 +13,7 @@ struct parse_tag { unsigned long parse_tag_value(const char *str, struct parse_tag *tags); unsigned long convert_unit(unsigned long value, char *unit); +double convert_unit_double(double value, char *unit); int unit_number__scnprintf(char *buf, size_t size, u64 n); #endif /* PERF_UNIT_H */ -- 2.25.1