Messages in this thread | | | Date | Thu, 4 Mar 2021 16:34:05 +0000 | From | Changbin Du <> | Subject | Re: [PATCH] perf stat: improve readability of shadow stats |
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On Tue, Mar 02, 2021 at 09:25:24AM -0300, Arnaldo Carvalho de Melo wrote: > Em Tue, Mar 02, 2021 at 11:08:40AM +0900, Namhyung Kim escreveu: > > On Tue, Mar 2, 2021 at 4:19 AM Jiri Olsa <jolsa@redhat.com> wrote: > > > > > > On Tue, Mar 02, 2021 at 01:24:02AM +0800, Changbin Du wrote: > > > > 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 > > > > > > should you remove also the leading '/' in ' /cpu-sec' ? > > > > The change looks good. And I think we should keep '/' otherwise it'd be > > more confusing. > > Perhaps: > > 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 > > ? > sure. Now it is: $ sudo ./perf stat [sudo] password for changbin: ^C Performance counter stats for 'system wide':
6,046.61 msec cpu-clock # 3.999 CPUs utilized 7,569 context-switches # 1.252 K/sec 587 cpu-migrations # 97.079 /sec 229 page-faults # 37.872 /sec 1,484,855,385 cycles # 0.246 GHz 2,112,863,483 stalled-cycles-frontend # 142.29% frontend cycles idle 1,980,746,623 stalled-cycles-backend # 133.40% backend cycles idle 454,477,035 instructions # 0.31 insn per cycle # 4.65 stalled cycles per insn 89,992,521 branches # 14.883 M/sec 6,196,599 branch-misses # 6.89% of all branches
1.512029866 seconds time elapsed
> - Arnaldo > > > > > > > > > > SNIP > > > > > > > @@ -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); > > > > > > hum this will change -x output that people parse, so I don't think we can do that > > > > Agreed. > > > > > > > > > } 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; > > > > +} > > > > > > we have convert_unit function just above doing the same only with > > > unsigned long.. let's have one base function with double values and > > > another one casting the result to unsigned long > > > > Sounds good. > > > > Thanks, > > Namhyung > > -- > > - Arnaldo
-- Cheers, Changbin Du
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