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| author |   Andi Kleen <andi@firstfloor.org> | 2020-10-26 17:27:36 -0700 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-11-04 09:42:41 -0300 |
| commit | 55a4de94c64bacffbcd802c954764e0de2ab217f (patch) | |
| tree | 1b0b27c54a7e43fc0d1287198269776779573731 | |
| parent | perf stat: Support regex pattern in --for-each-cgroup (diff) | |
| download | linux-dev-55a4de94c64bacffbcd802c954764e0de2ab217f.tar.xz linux-dev-55a4de94c64bacffbcd802c954764e0de2ab217f.zip | |
perf stat: Add --quiet option
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.
Signed-off-by: Andi Kleen <andi@firstfloor.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Link: http://lore.kernel.org/lkml/20201027002737.30942-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/Documentation/perf-stat.txt | 4 | ||||
| -rw-r--r-- | tools/perf/builtin-stat.c | 6 | ||||
| -rw-r--r-- | tools/perf/util/stat.h | 1 |
3 files changed, 10 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 2b44c08b3b23..5d4a673d7621 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -317,6 +317,10 @@ 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 6709578128c9..f15b2f8aa14d 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; |