Subject: Add histogram support to cyclictest
From: Sven-Thorsten Dietrich <sdietrich@xxxxxxx>
Add -h <size> parameter and functionality to log histograms of latencies
in cyclictest.
Signed-off-by: Sven-Thorsten Dietrich <sdietrich@xxxxxxx>
diff --git a/src/cyclictest/cyclictest.8 b/src/cyclictest/cyclictest.8
index 9827458..82c2c43 100644
--- a/src/cyclictest/cyclictest.8
+++ b/src/cyclictest/cyclictest.8
@@ -16,7 +16,7 @@
cyclictest \- High resolution test program
.SH SYNOPSIS
.B cyclictest
-.RI "[ \-hfmnqrsv ] [\-a " proc " ] [\-b " usec " ] [\-c " clock " ] [\-d " dist " ] [\-i " intv " ] [\-l " loop " ] [\-o " red " ] [\-p " prio " ] [\-t " num " ]"
+.RI "[ \-hfmnqrsv ] [\-a " proc " ] [\-b " usec " ] [\-c " clock " ] [\-d " dist " ] [\-h " histogram " ] [\-i " intv " ] [\-l " loop " ] [\-o " red " ] [\-p " prio " ] [\-t " num " ]"
.\" .SH DESCRIPTION
.\" This manual page documents briefly the
.\" .B cyclictest commands.
@@ -81,6 +81,9 @@ Set the distance of thread intervals in microseconds (default is 500us). When cy
.B \-f, \-\-ftrace
Enable function tracing using ftrace as tracer. This option is available only with \-b.
.TP
+.B \-h=MAXLATENCYINUS
+Dump latency histogram to stdout.
+.TP
.B \-i, \-\-interval=INTV
Set the base interval of the thread(s) in microseconds (default is 1000us). This sets the interval of the first thread. See also \-d.
.TP
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 149c2ec..c604131 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -93,6 +93,8 @@ enum {
IRQPREEMPTOFF,
};
+#define HIST_MAX 1000000
+
/* Struct to transfer parameters to the thread */
struct thread_param {
int prio;
@@ -116,6 +118,7 @@ struct thread_stat {
long act;
double avg;
long *values;
+ long *hist_array;
pthread_t thread;
int threadstarted;
int tid;
@@ -132,6 +135,7 @@ static int verbose = 0;
static int oscope_reduction = 1;
static int tracetype;
static int lockall = 0;
+static int histogram = 0;
/* Backup of kernel variables that we modify */
static struct kvars {
@@ -536,6 +540,9 @@ void *timerthread(void *param)
if (par->bufmsk)
stat->values[stat->cycles & par->bufmsk] = diff;
+
+ if (histogram && (diff < histogram))
+ stat->hist_array[diff] += 1;
next.tv_sec += interval.tv_sec;
next.tv_nsec += interval.tv_nsec;
@@ -582,6 +589,7 @@ static void display_help(void)
" 1 = CLOCK_REALTIME\n"
"-d DIST --distance=DIST distance of thread intervals in us default=500\n"
"-f --ftrace function trace (when -b is active)\n"
+ "-h H_MAX latency histogram size in us default 0 (off)\n"
"-i INTV --interval=INTV base interval of thread in us default=1000\n"
"-I --irqsoff Irqsoff tracing (used with -b)\n"
"-l LOOPS --loops=LOOPS number of loops: default=0(endless)\n"
@@ -642,6 +650,7 @@ static void process_options (int argc, char *argv[])
{"clock", required_argument, NULL, 'c'},
{"distance", required_argument, NULL, 'd'},
{"ftrace", no_argument, NULL, 'f'},
+ {"histogram", required_argument, NULL, 'h'},
{"interval", required_argument, NULL, 'i'},
{"irqsoff", no_argument, NULL, 'I'},
{"loops", required_argument, NULL, 'l'},
@@ -658,7 +667,7 @@ static void process_options (int argc, char *argv[])
{"help", no_argument, NULL, '?'},
{NULL, 0, NULL, 0}
};
- int c = getopt_long (argc, argv, "a::b:Bc:d:fi:Il:nmo:p:Pqrst::v",
+ int c = getopt_long (argc, argv, "a::b:Bc:d:fh:i:Il:nmo:p:Pqrst::v",
long_options, &option_index);
if (c == -1)
break;
@@ -679,6 +688,7 @@ static void process_options (int argc, char *argv[])
case 'c': clocksel = atoi(optarg); break;
case 'd': distance = atoi(optarg); break;
case 'f': ftrace = 1; break;
+ case 'h': histogram = atoi(optarg); break;
case 'i': interval = atoi(optarg); break;
case 'I': tracetype = IRQSOFF; break;
case 'l': max_cycles = atoi(optarg); break;
@@ -724,6 +734,9 @@ static void process_options (int argc, char *argv[])
error = 1;
}
+ if (histogram < 0)
+ error = 1;
+
if (priority < 0 || priority > 99)
error = 1;
@@ -776,6 +789,36 @@ static void sighand(int sig)
tracing(0);
}
+static void print_hist(struct thread_param *par, int nthreads)
+{
+ int i, j;
+ unsigned long long log_entries[nthreads];
+ unsigned long max_latency = 0;
+
+ bzero(log_entries, sizeof(log_entries));
+
+ printf("# Histogram\n");
+ for (i = 0; i < histogram; i++) {
+
+ printf("%05d ", i);
+
+ for (j = 0; j < nthreads; j++) {
+ unsigned long curr_latency=par[j].stats->hist_array[i];
+ printf("%06lu\t", curr_latency);
+ log_entries[j] += curr_latency;
+ if (curr_latency && max_latency < i)
+ max_latency = i;
+ }
+ printf("\n");
+
+ }
+ printf("# Total:");
+ for (j = 0; j < nthreads; j++)
+ printf(" %09llu", log_entries[j]);
+ printf("\n");
+ printf("# Max Latency: %lu / %d\n", max_latency, histogram);
+}
+
static void print_stat(struct thread_param *par, int index, int verbose)
{
struct thread_stat *stat = par->stats;
@@ -874,6 +917,12 @@ int main(int argc, char **argv)
goto outpar;
for (i = 0; i < num_threads; i++) {
+ if (histogram) {
+ if (histogram > HIST_MAX)
+ histogram = HIST_MAX;
+ stat[i].hist_array = calloc(histogram, sizeof(long));
+ }
+
if (verbose) {
stat[i].values = calloc(VALBUF_SIZE, sizeof(long));
if (!stat[i].values)
@@ -882,14 +931,17 @@ int main(int argc, char **argv)
}
par[i].prio = priority;
- if (priority)
+ if (priority && !histogram)
priority--;
par[i].clock = clocksources[clocksel];
par[i].mode = mode;
par[i].timermode = timermode;
par[i].signal = signum;
par[i].interval = interval;
- interval += distance;
+ if (!histogram) /* histogram requires same interval on CPUs*/
+ interval += distance;
+ if (verbose)
+ printf("Thread %d Interval: %d\n", i, interval);
par[i].max_cycles = max_cycles;
par[i].stats = &stat[i];
switch (setaffinity) {
@@ -932,6 +984,7 @@ int main(int argc, char **argv)
outall:
shutdown = 1;
usleep(50000);
+
if (quiet)
quiet = 2;
for (i = 0; i < num_threads; i++) {
@@ -939,12 +992,19 @@ int main(int argc, char **argv)
pthread_kill(stat[i].thread, SIGTERM);
if (stat[i].threadstarted) {
pthread_join(stat[i].thread, NULL);
- if (quiet)
+ if (quiet && !histogram)
print_stat(&par[i], i, 0);
}
if (stat[i].values)
free(stat[i].values);
}
+
+ if (histogram) {
+ print_hist(par, num_threads);
+ for (i = 0; i < num_threads; i++)
+ free (stat[i].hist_array);
+ }
+
free(stat);
outpar:
free(par);
--
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