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| author | Jaswinder Singh Rajput <jaswinder@kernel.org> | 2009-06-27 22:19:09 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-06-28 17:22:47 +0400 |
| commit | c3043569dc8fbe9228b76174f15d1a7152c48a20 (patch) | |
| tree | c8a54134d28114665ef1a8ea5d9e6a12bedbef98 | |
| parent | 6e750a8fc009fd0ae98704525d1d8e80d60e8cc9 (diff) | |
| download | linux-c3043569dc8fbe9228b76174f15d1a7152c48a20.tar.xz | |
perf stat: Micro-optimize the code: memcpy is only required if no event is selected and !null_run
Set attrs and nr_counters if no event is selected and !null_run.
Setting of attrs should depend on number of counters,
so we need to memcpy only for sizeof(default_attrs)
Also set nr_counters as ARRAY_SIZE(default_attrs) in place of
hardcoded value.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1246126749.32198.16.camel@hpdv5.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | tools/perf/builtin-stat.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 3840a70f05b7..3e5ea4e2e5fd 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -46,7 +46,7 @@ #include <sys/prctl.h> #include <math.h> -static struct perf_counter_attr default_attrs[MAX_COUNTERS] = { +static struct perf_counter_attr default_attrs[] = { { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK }, { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES}, @@ -477,16 +477,17 @@ int cmd_stat(int argc, const char **argv, const char *prefix) { int status; - memcpy(attrs, default_attrs, sizeof(attrs)); - argc = parse_options(argc, argv, options, stat_usage, 0); if (!argc) usage_with_options(stat_usage, options); if (run_count <= 0 || run_count > MAX_RUN) usage_with_options(stat_usage, options); - if (!null_run && !nr_counters) - nr_counters = 8; + /* Set attrs and nr_counters if no event is selected and !null_run */ + if (!null_run && !nr_counters) { + memcpy(attrs, default_attrs, sizeof(default_attrs)); + nr_counters = ARRAY_SIZE(default_attrs); + } nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); assert(nr_cpus <= MAX_NR_CPUS); |