Messages in this thread | | | Date | Tue, 27 Oct 2020 12:09:25 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 1/2] perf tools: Add --quiet option to perf stat |
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Em Mon, Oct 26, 2020 at 05:27:36PM -0700, Andi Kleen escreveu: > Add a new --quiet option to perf stat. This is useful with perf stat > record to write the data only to the perf.data file, which can lower > measurement overhead because the data doesn't need to be formatted. > > On my 4C desktop: > > % time ./perf stat record -e $(python -c 'print ",".join(["cycles"]*1000)') -a -I 1000 sleep 5 > ... > real 0m5.377s > user 0m0.238s > sys 0m0.452s > % time ./perf stat record --quiet -e $(python -c 'print ",".join(["cycles"]*1000)') -a -I 1000 sleep 5 > > real 0m5.452s > user 0m0.183s > sys 0m0.423s > > In this example it cuts the user time by 20%. On systems with more cores > the savings are higher.
Applied 1/2,
Thanks,
- Arnaldo
> Signed-off-by: Andi Kleen <andi@firstfloor.org> > --- > tools/perf/Documentation/perf-stat.txt | 4 ++++ > tools/perf/builtin-stat.c | 6 +++++- > tools/perf/util/stat.h | 1 + > 3 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt > index 9f9f29025e49..b138dd192423 100644 > --- a/tools/perf/Documentation/perf-stat.txt > +++ b/tools/perf/Documentation/perf-stat.txt > @@ -316,6 +316,10 @@ small group that need not have multiplexing is lowered. This option > forbids the event merging logic from sharing events between groups and > may be used to increase accuracy in this case. > > +--quiet:: > +Don't print output. This is useful with perf stat record below to only > +write data to the perf.data file. > + > STAT RECORD > ----------- > Stores stat data into perf data file. > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index b01af171d94f..743fe47e7a88 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -972,6 +972,8 @@ static void print_counters(struct timespec *ts, int argc, const char **argv) > /* Do not print anything if we record to the pipe. */ > if (STAT_RECORD && perf_stat.data.is_pipe) > return; > + if (stat_config.quiet) > + return; > > perf_evlist__print_counters(evsel_list, &stat_config, &target, > ts, argc, argv); > @@ -1171,6 +1173,8 @@ static struct option stat_options[] = { > "threads of same physical core"), > OPT_BOOLEAN(0, "summary", &stat_config.summary, > "print summary for interval mode"), > + OPT_BOOLEAN(0, "quiet", &stat_config.quiet, > + "don't print output (useful with record)"), > #ifdef HAVE_LIBPFM > OPT_CALLBACK(0, "pfm-events", &evsel_list, "event", > "libpfm4 event selector. use 'perf list' to list available events", > @@ -2132,7 +2136,7 @@ int cmd_stat(int argc, const char **argv) > goto out; > } > > - if (!output) { > + if (!output && !stat_config.quiet) { > struct timespec tm; > mode = append_file ? "a" : "w"; > > diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h > index 487010c624be..05adf8165025 100644 > --- a/tools/perf/util/stat.h > +++ b/tools/perf/util/stat.h > @@ -122,6 +122,7 @@ struct perf_stat_config { > bool metric_no_group; > bool metric_no_merge; > bool stop_read_counter; > + bool quiet; > FILE *output; > unsigned int interval; > unsigned int timeout; > -- > 2.28.0 >
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- Arnaldo
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