diff options
| author | Bhavesh Davda <bhavesh@vmware.com> | 2012-10-16 10:02:53 -0700 |
|---|---|---|
| committer | John Kacur <jkacur@redhat.com> | 2012-10-17 00:19:23 +0200 |
| commit | 992b905d42143f2741b537b60bc51e3fa7c8859d (patch) | |
| tree | 87c2a8cf85f325c415959e0d31f491d12a53a647 | |
| parent | 18cd9775e55f7bb07f01cc5ef8b1f66fd9a4b318 (diff) | |
| download | rt-tests-992b905d42143f2741b537b60bc51e3fa7c8859d.tar.gz | |
cyclictest: histogram overflow instance tracking
Add feature to cyclictest histogram mode to track cycle counts every time a
sample overflows the histogram limit. This should help identify if there is a
timing pattern to jitters in cyclictest runs.
Example output (with -h 10):
...
Histogram Overflows: 00001 00007 00000 00009 00004 00007 00000 00001
Histogram Overflow at cycle number:
Thread 0: 09964
Thread 1: 00000 00004 00006 00008 00010 09962 11594
Thread 2:
Thread 3: 01169 04698 06782 09033 10299 11561 21517 28734 29532
Thread 4: 11574 11580 11583 11586
Thread 5: 00020 09448 13954 14954 18954 20587 24973
Thread 6:
Thread 7: 18950
...
Signed-off-by: Bhavesh Davda <bhavesh@vmware.com>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: John Kacur <jkacur@redhat.com>
| -rw-r--r-- | src/cyclictest/cyclictest.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c index 418538f..824544f 100644 --- a/src/cyclictest/cyclictest.c +++ b/src/cyclictest/cyclictest.c @@ -150,6 +150,7 @@ struct thread_stat { double avg; long *values; long *hist_array; + long *outliers; pthread_t thread; int threadstarted; int tid; @@ -157,6 +158,7 @@ struct thread_stat { long redmax; long cycleofmax; long hist_overflow; + long num_outliers; }; static int shutdown; @@ -850,8 +852,11 @@ void *timerthread(void *param) /* Update the histogram */ if (histogram) { - if (diff >= histogram) + if (diff >= histogram) { stat->hist_overflow++; + if (stat->num_outliers < histogram) + stat->outliers[stat->num_outliers++] = stat->cycles; + } else stat->hist_array[diff]++; } @@ -1401,6 +1406,17 @@ static void print_hist(struct thread_param *par[], int nthreads) if (histofall && nthreads > 1) printf(" %05lu", alloverflows); printf("\n"); + + printf("# Histogram Overflow at cycle number:\n"); + for (i = 0; i < nthreads; i++) { + printf("# Thread %d:", i); + for (j = 0; j < par[i]->stats->num_outliers; j++) + printf(" %05lu", par[i]->stats->outliers[j]); + if (par[i]->stats->num_outliers < par[i]->stats->hist_overflow) + printf(" # %05lu others", par[i]->stats->hist_overflow - par[i]->stats->num_outliers); + printf("\n"); + } + printf("\n"); } static void print_stat(struct thread_param *par, int index, int verbose) @@ -1549,10 +1565,12 @@ int main(int argc, char **argv) int bufsize = histogram * sizeof(long); stat->hist_array = threadalloc(bufsize, node); - if (stat->hist_array == NULL) + stat->outliers = threadalloc(bufsize, node); + if (stat->hist_array == NULL || stat->outliers == NULL) fatal("failed to allocate histogram of size %d on node %d\n", histogram, i); memset(stat->hist_array, 0, bufsize); + memset(stat->outliers, 0, bufsize); } if (verbose) { @@ -1668,8 +1686,10 @@ int main(int argc, char **argv) if (histogram) { print_hist(parameters, num_threads); - for (i = 0; i < num_threads; i++) + for (i = 0; i < num_threads; i++) { threadfree(statistics[i]->hist_array, histogram*sizeof(long), parameters[i]->node); + threadfree(statistics[i]->outliers, histogram*sizeof(long), parameters[i]->node); + } } if (tracelimit) { |