[PATCH -tip] perf stat: memcpy is only required if no event isselected and !null_run

From: Jaswinder Singh Rajput
Date: Sat Jun 27 2009 - 14:20:03 EST



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)

and set nr_counters as ARRAY_SIZE(default_attrs) in place of hardcoded value

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@xxxxxxxxx>
---
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 3840a70..3e5ea4e 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);
--
1.6.0.6



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