[tip:perfcounters/core] perf stat: Clean up statistics calculations a bit more

tip-bot for Peter Zijlstra
2009-09-04T18:34:37Z

Commit-ID: 849abde92bd3314a4894f2b4f70b30c2accf8653
Gitweb: http://git.kernel.org/tip/849abde92bd3314a4894f2b4f70b30c2accf8653
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 4 Sep 2009 18:23:38 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 4 Sep 2009 20:27:26 +0200

perf stat: Clean up statistics calculations a bit more

Remove some, now useless, global storage.
Don't calculate the stddev when not needed.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
tools/perf/builtin-stat.c | 31 ++++++++++++++-----------------
1 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 32b5c00..61b8282 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -74,7 +74,6 @@ static int null_run = 0;

static int fd[MAX_NR_CPUS][MAX_COUNTERS];

-static u64 event_res[MAX_COUNTERS][3];
static int event_scaled[MAX_COUNTERS];

struct stats
@@ -179,14 +178,12 @@ static inline int nsec_counter(int counter)
*/
static void read_counter(int counter)
{
- u64 *count, single_count[3];
+ u64 count[3], single_count[3];
unsigned int cpu;
size_t res, nv;
int scaled;
int i;

- count = event_res[counter];
-
count[0] = count[1] = count[2] = 0;

nv = scale ? 3 : 1;
@@ -318,13 +315,16 @@ static int run_perf_stat(int argc __used, const char **argv)
return WEXITSTATUS(status);
}

-static void print_noise(double avg, double stddev)
+static void print_noise(int counter, double avg)
{
- if (run_count > 1)
- fprintf(stderr, " ( +- %7.3f%% )", 100*stddev / avg);
+ if (run_count == 1)
+ return;
+
+ fprintf(stderr, " ( +- %7.3f%% )",
+ 100 * stddev_stats(&event_res_stats[counter][0]) / avg);
}

-static void nsec_printout(int counter, double avg, double stddev)
+static void nsec_printout(int counter, double avg)
{
double msecs = avg / 1e6;

@@ -334,10 +334,9 @@ static void nsec_printout(int counter, double avg, double stddev)
fprintf(stderr, " # %10.3f CPUs ",
avg / avg_stats(&walltime_nsecs_stats));
}
- print_noise(avg, stddev);
}

-static void abs_printout(int counter, double avg, double stddev)
+static void abs_printout(int counter, double avg)
{
fprintf(stderr, " %14.0f %-24s", avg, event_name(counter));

@@ -348,7 +347,6 @@ static void abs_printout(int counter, double avg, double stddev)
fprintf(stderr, " # %10.3f M/sec",
1000.0 * avg / avg_stats(&runtime_nsecs_stats));
}
- print_noise(avg, stddev);
}

/*
@@ -356,12 +354,9 @@ static void abs_printout(int counter, double avg, double stddev)
*/
static void print_counter(int counter)
{
- double avg, stddev;
+ double avg = avg_stats(&event_res_stats[counter][0]);
int scaled = event_scaled[counter];

- avg = avg_stats(&event_res_stats[counter][0]);
- stddev = stddev_stats(&event_res_stats[counter][0]);
-
if (scaled == -1) {
fprintf(stderr, " %14s %-24s\n",
"<not counted>", event_name(counter));
@@ -369,9 +364,11 @@ static void print_counter(int counter)
}

if (nsec_counter(counter))
- nsec_printout(counter, avg, stddev);
+ nsec_printout(counter, avg);
else
- abs_printout(counter, avg, stddev);
+ abs_printout(counter, avg);
+
+ print_noise(counter, avg);

if (scaled) {
double avg_enabled, avg_running;