This enhancement comes courtesy of Frank Rowand. It simplifies post-processing
of the outliers output. Note that the time reported is the "expected" wake-up
time for the outlier, not the "actual" wake-up time.
$ sudo ./cyclictest -p 99 -m -n -a -h 5 -g 50 -t4 -D 30
/dev/cpu_dma_latency set to 0us
policy: fifo: loadavg: 0.14 0.07 0.02 1/392 17548
T: 0 (17514) P:99 I:1000 C: 29994 Min: 2 Act: 4 Avg: 3 Max: 25
T: 1 (17515) P:99 I:1000 C: 29992 Min: 2 Act: 4 Avg: 158 Max: 53753
T: 2 (17516) P:99 I:1000 C: 29990 Min: 2 Act: 3 Avg: 3 Max: 8
T: 3 (17517) P:99 I:1000 C: 29988 Min: 2 Act: 3 Avg: 4 Max: 5217
Histogram
000000 000000 000000 000000 000000
000001 000000 000000 000000 000000
000002 000270 000026 000059 001742
000003 018558 002344 010656 007578
000004 011044 023196 019209 018014
Total: 000029872 000025566 000029924 000027334
Min Latencies: 00002 00002 00002 00002
Avg Latencies: 00003 00158 00003 00004
Max Latencies: 00025 53753 00008 05217
Histogram Overflows: 00128 04432 00072 02660
Histogram Overflow: time (sec), thread
0.003019264 0
0.004019264 0
...
0.005076667 1
0.006076667 1
...
0.007151408 2
0.008151408 2
...
0.009228138 3
0.019228138 3
...
Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxxxxx>
Signed-off-by: Bhavesh Davda <bhavesh@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 42 ++++++++++++++++++++++++++++++++----------
1 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 141e79f..b27f7dc 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -110,6 +110,8 @@ extern int clock_nanosleep(clockid_t __clock_id, int __flags,
int enable_events;
+struct timespec test_start;
+
static char *policyname(int policy);
enum {
@@ -151,7 +153,7 @@ struct thread_stat {
double avg;
long *values;
long *hist_array;
- long *outliers;
+ struct timespec *outliers;
pthread_t thread;
int threadstarted;
int tid;
@@ -337,6 +339,18 @@ static inline void tsnorm(struct timespec *ts)
}
}
+static inline void tsnorm2(struct timespec *ts)
+{
+ while (ts->tv_nsec < 0) {
+ ts->tv_nsec += NSEC_PER_SEC;
+ ts->tv_sec--;
+ }
+ while (ts->tv_nsec >= NSEC_PER_SEC) {
+ ts->tv_nsec -= NSEC_PER_SEC;
+ ts->tv_sec++;
+ }
+}
+
static inline int64_t calcdiff(struct timespec t1, struct timespec t2)
{
int64_t diff;
@@ -890,7 +904,7 @@ void *timerthread(void *param)
if (diff >= histogram) {
stat->hist_overflow++;
if (stat->num_outliers < of_max)
- stat->outliers[stat->num_outliers++] = stat->cycles;
+ stat->outliers[stat->num_outliers++] = next;
}
else
stat->hist_array[diff]++;
@@ -1462,14 +1476,15 @@ static void print_hist(struct thread_param *par[], int nthreads)
printf(" %05lu", alloverflows);
printf("\n");
- printf("# Histogram Overflow at time (ms):\n");
+ printf("# Histogram Overflow: time (sec), thread\n");
for (i = 0; i < nthreads; i++) {
- printf("# Thread %d:", i);
- for (j = 0; j < par[i]->stats->num_outliers; j++)
- printf(" %lu", par[i]->stats->outliers[j] * par[i]->interval / 1000);
- if (par[i]->stats->num_outliers < par[i]->stats->hist_overflow)
- printf(" # %lu others", par[i]->stats->hist_overflow - par[i]->stats->num_outliers);
- printf("\n");
+ for (j = 0; j < par[i]->stats->num_outliers; j++) {
+ struct timespec diff;
+ diff.tv_sec = par[i]->stats->outliers[j].tv_sec - test_start.tv_sec;
+ diff.tv_nsec = par[i]->stats->outliers[j].tv_nsec - test_start.tv_nsec;
+ tsnorm2(&diff);
+ printf("%ld.%09ld %d\n", diff.tv_sec, diff.tv_nsec, i);
+ }
}
}
@@ -1663,6 +1678,13 @@ int main(int argc, char **argv)
if (!statistics)
goto outpar;
+ /*
+ * test_start does not need to be precise. For some types of output,
+ * it will be subtracted from a time value so that the result is
+ * relative to the start of test.
+ */
+ clock_gettime(clocksources[clocksel], &test_start);
+
for (i = 0; i < num_threads; i++) {
pthread_attr_t attr;
int node;
@@ -1722,7 +1744,7 @@ int main(int argc, char **argv)
memset(stat->hist_array, 0, bufsize);
}
if (of_max) {
- int bufsize = of_max * sizeof(long);
+ int bufsize = of_max * sizeof(*stat->outliers);
stat->outliers = threadalloc(bufsize, node);
if (stat->outliers == NULL)
fatal("failed to allocate outliers of size %d on node %d\n",
--
1.7.4.1
--
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