Thanks for the review, Frank.
On Oct 11, 2012, at 12:57 PM, Frank Rowand wrote:
> Nice idea…
Thanks
> Suggest:
> printf("# Histogram Overflows at cycle number:");
>
Done
>> - printf(" %05lu", par[j]->stats->hist_overflow);
>> + printf(" %05lu", par[j]->stats->hist_overflow);
>
> Am I blind, or is that a whitespace change? (The latest version I have does not seem
> to have any white space issues in that line.)
>
Turns out I had removed extraneous whitespace. My vim settings allow me to see extraneous whitespaces in red, so I get annoyed by them and can fix them up. So I've removed a few more in the revised diffs (sorry!)
> Suggest:
>
> + printf("# thread %d:", j);
>
Done
> Nit: You don't need stats->outliers_overflow. You can calculate it from
> stats->hist_overflow - stats->num_outliers:
>
Nice catch! I've removed outliers_overflow now.
From: Bhavesh Davda <bhavesh@xxxxxxxxxx>
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: 00000 00253 00000 00005 00000 00024 00003 00005
Histogram Overflow at cycle number:
Thread 0:
Thread 1: 00023 00028 00337 00338 00339 00340 00341 00342 00343 00344 # 00243 others
Thread 2:
Thread 3: 10486 10487 10488 10489 10490
Thread 4:
Thread 5: 00002 00004 00008 00012 00178 10458 10459 10460 10461 10462 # 00014 others
Thread 6: 05954 08954 29955
Thread 7: 20536 20537 20538 20539 20540
...
Signed-off-by: Bhavesh Davda <bhavesh@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 38 +++++++++++++++++++++++++++++---------
1 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 731b4bd..dc985de 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -147,6 +147,7 @@ struct thread_stat {
double avg;
long *values;
long *hist_array;
+ unsigned long *outliers;
pthread_t thread;
int threadstarted;
int tid;
@@ -154,6 +155,7 @@ struct thread_stat {
long redmax;
long cycleofmax;
long hist_overflow;
+ long num_outliers;
};
static int shutdown;
@@ -756,8 +758,11 @@ 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 - 1;
+ }
else
stat->hist_array[diff]++;
}
@@ -811,7 +816,7 @@ static void display_help(int error)
if (kernvar(O_RDONLY, "available_tracers", tracers, sizeof(tracers)))
strcpy(tracers, "none");
}
-
+
printf("cyclictest V %1.2f\n", VERSION_STRING);
printf("Usage:\n"
"cyclictest <options>\n\n"
@@ -1188,7 +1193,7 @@ static int check_kernel(void)
kv = KV_30;
strcpy(functiontracer, "function");
strcpy(traceroptions, "trace_options");
-
+
} else
kv = KV_NOT_SUPPORTED;
@@ -1226,7 +1231,7 @@ static void print_tids(struct thread_param *par[], int nthreads)
static void print_hist(struct thread_param *par[], int nthreads)
{
- int i, j;
+ int i, j, k;
unsigned long long int log_entries[nthreads+1];
unsigned long maxmax, alloverflows;
@@ -1270,7 +1275,7 @@ static void print_hist(struct thread_param *par[], int nthreads)
printf("# Max Latencies:");
maxmax = 0;
for (j = 0; j < nthreads; j++) {
- printf(" %05lu", par[j]->stats->max);
+ printf(" %05lu", par[j]->stats->max);
if (par[j]->stats->max > maxmax)
maxmax = par[j]->stats->max;
}
@@ -1280,9 +1285,20 @@ static void print_hist(struct thread_param *par[], int nthreads)
printf("# Histogram Overflows:");
alloverflows = 0;
for (j = 0; j < nthreads; j++) {
- printf(" %05lu", par[j]->stats->hist_overflow);
+ printf(" %05lu", par[j]->stats->hist_overflow);
alloverflows += par[j]->stats->hist_overflow;
}
+ printf("\n");
+ printf("# Histogram Overflow at cycle number:\n");
+ for (j = 0; j < nthreads; j++) {
+ printf("# Thread %d:", j);
+ for (k = 0; k < par[j]->stats->num_outliers; k++)
+ printf(" %05lu", par[j]->stats->outliers[k]);
+ if (par[j]->stats->num_outliers < par[j]->stats->hist_overflow)
+ printf(" # %05lu others", par[j]->stats->hist_overflow - par[j]->stats->num_outliers);
+ printf("\n");
+ }
+
if (histofall && nthreads > 1)
printf(" %05lu", alloverflows);
printf("\n");
@@ -1434,10 +1450,12 @@ 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) {
@@ -1553,8 +1571,10 @@ 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) {
@@ -1564,7 +1584,7 @@ int main(int argc, char **argv)
printf("# Break value: %lu\n", break_thread_value);
}
}
-
+
for (i=0; i < num_threads; i++) {
if (!statistics[i])
--
1.7.1
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