[tip:perfcounters/core] perf stat: Remove the limit on repeat

tip-bot for Peter Zijlstra
2009-09-04T15:43:41Z

Commit-ID: 9e9772c458d50dabdb5327821da3803254638cd1
Gitweb: http://git.kernel.org/tip/9e9772c458d50dabdb5327821da3803254638cd1
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 4 Sep 2009 15:36:08 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 4 Sep 2009 16:33:08 +0200

perf stat: Remove the limit on repeat

Since we don't need all the individual samples to calculate the
error remove both the limit and the storage overhead associated
with that.

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 | 84 ++++++++++++++------------------------------
1 files changed, 27 insertions(+), 57 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 31ffc4d..9c6377f 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -62,8 +62,6 @@ static struct perf_counter_attr default_attrs[] = {

};

-#define MAX_RUN 100
-
static int system_wide = 0;
static unsigned int nr_cpus = 0;
static int run_idx = 0;
@@ -76,12 +74,8 @@ static int null_run = 0;

static int fd[MAX_NR_CPUS][MAX_COUNTERS];

-static u64 runtime_nsecs[MAX_RUN];
-static u64 walltime_nsecs[MAX_RUN];
-static u64 runtime_cycles[MAX_RUN];
-
-static u64 event_res[MAX_RUN][MAX_COUNTERS][3];
-static u64 event_scaled[MAX_RUN][MAX_COUNTERS];
+static u64 event_res[MAX_COUNTERS][3];
+static u64 event_scaled[MAX_COUNTERS];

struct stats
{
@@ -89,6 +83,14 @@ struct stats
double sum_sq;
};

+static void update_stats(struct stats *stats, u64 val)
+{
+ double sq = val;
+
+ stats->sum += val;
+ stats->sum_sq += sq * sq;
+}
+
static double avg_stats(struct stats *stats)
{
return stats->sum / run_count;
@@ -167,8 +169,9 @@ static void read_counter(int counter)
unsigned int cpu;
size_t res, nv;
int scaled;
+ int i;

- count = event_res[run_idx][counter];
+ count = event_res[counter];

count[0] = count[1] = count[2] = 0;

@@ -193,24 +196,33 @@ static void read_counter(int counter)
scaled = 0;
if (scale) {
if (count[2] == 0) {
- event_scaled[run_idx][counter] = -1;
+ event_scaled[counter] = -1;
count[0] = 0;
return;
}

if (count[2] < count[1]) {
- event_scaled[run_idx][counter] = 1;
+ event_scaled[counter] = 1;
count[0] = (unsigned long long)
((double)count[0] * count[1] / count[2] + 0.5);
}
}
+
+ for (i = 0; i < 3; i++)
+ update_stats(&event_res_stats[counter][i], count[i]);
+
+ if (verbose) {
+ fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
+ count[0], count[1], count[2]);
+ }
+
/*
* Save the full runtime - to allow normalization during printout:
*/
if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
- runtime_nsecs[run_idx] = count[0];
+ update_stats(&runtime_nsecs_stats, count[0]);
if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
- runtime_cycles[run_idx] = count[0];
+ update_stats(&runtime_cycles_stats, count[0]);
}

static int run_perf_stat(int argc __used, const char **argv)
@@ -284,7 +296,7 @@ static int run_perf_stat(int argc __used, const char **argv)

t1 = rdclock();

- walltime_nsecs[run_idx] = t1 - t0;
+ update_stats(&walltime_nsecs_stats, t1 - t0);

for (counter = 0; counter < nr_counters; counter++)
read_counter(counter);
@@ -361,52 +373,10 @@ static void print_counter(int counter)
fprintf(stderr, "\n");
}

-static void update_stats(const char *name, int idx, struct stats *stats, u64 *val)
-{
- double sq = *val;
-
- stats->sum += *val;
- stats->sum_sq += sq * sq;
-
- if (verbose > 1)
- fprintf(stderr, "debug: %20s[%d]: %Ld\n", name, idx, *val);
-}
-
-/*
- * Calculate the averages and noises:
- */
-static void calc_avg(void)
-{
- int i, j;
-
- if (verbose > 1)
- fprintf(stderr, "\n");
-
- for (i = 0; i < run_count; i++) {
- update_stats("runtime", 0, &runtime_nsecs_stats, runtime_nsecs + i);
- update_stats("walltime", 0, &walltime_nsecs_stats, walltime_nsecs + i);
- update_stats("runtime_cycles", 0, &runtime_cycles_stats, runtime_cycles + i);
-
- for (j = 0; j < nr_counters; j++) {
- update_stats("counter/0", j,
- event_res_stats[j]+0, event_res[i][j]+0);
- update_stats("counter/1", j,
- event_res_stats[j]+1, event_res[i][j]+1);
- update_stats("counter/2", j,
- event_res_stats[j]+2, event_res[i][j]+2);
- if (event_scaled[i][j] != (u64)-1)
- update_stats("scaled", j,
- event_scaled_stats + j, event_scaled[i]+j);
- }
- }
-}
-
static void print_stat(int argc, const char **argv)
{
int i, counter;

- calc_avg();
-
fflush(stdout);

fprintf(stderr, "\n");
@@ -484,7 +454,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
PARSE_OPT_STOP_AT_NON_OPTION);
if (!argc)
usage_with_options(stat_usage, options);
- if (run_count <= 0 || run_count > MAX_RUN)
+ if (run_count <= 0)
usage_with_options(stat_usage, options);

/* Set attrs and nr_counters if no event is selected and !null_run */