diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-06-27 06:10:30 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-06-27 06:11:24 +0200 |
| commit | 0cfb7a13b8e4e0afd4b856156ab16a182de7505b (patch) | |
| tree | 7ebae71e6ef94d3bb95e43b4b2735c378f217449 /tools/perf | |
| parent | fde953c1c67986e1c381fa50d8207b1578b5cefa (diff) | |
perf stat: Add -n/--null option to run without counters
Allow a no-counters run. This can be useful to measure just
elapsed wall-clock time - or to assess the raw overhead of perf
stat itself, without running any counters.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/builtin-stat.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 8420ec589506..cdcd058fac08 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -70,6 +70,7 @@ static int run_count = 1; static int inherit = 1; static int scale = 1; static int target_pid = -1; +static int null_run = 0; static int fd[MAX_NR_CPUS][MAX_COUNTERS]; @@ -461,6 +462,8 @@ static const struct option options[] = { "be more verbose (show counter open errors, etc)"), OPT_INTEGER('r', "repeat", &run_count, "repeat command and print average + stddev (max: 100)"), + OPT_BOOLEAN('n', "null", &null_run, + "null run - dont start any counters"), OPT_END() }; @@ -476,7 +479,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix) if (run_count <= 0 || run_count > MAX_RUN) usage_with_options(stat_usage, options); - if (!nr_counters) + if (!null_run && !nr_counters) nr_counters = 8; nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); |