The new code is also intended to be used by cyclicdeadline, and possibly
oslat and other tests.
Signed-off-by: Crystal Wood <crwood@xxxxxxxxxx>
---
v2: Fix some checkpatch warnings
Makefile | 3 +-
src/cyclictest/cyclictest.c | 82 +++++------------
src/include/histogram.h | 42 +++++++++
src/lib/histogram.c | 172 ++++++++++++++++++++++++++++++++++++
4 files changed, 239 insertions(+), 60 deletions(-)
create mode 100644 src/include/histogram.h
create mode 100644 src/lib/histogram.c
diff --git a/Makefile b/Makefile
index ad481a73cf93..9502adea49cf 100644
--- a/Makefile
+++ b/Makefile
@@ -178,7 +178,8 @@ oslat: $(OBJDIR)/oslat.o $(OBJDIR)/librttest.a $(OBJDIR)/librttestnuma.a
%.8.bz2: %.8
bzip2 -c $< > $@
-LIBOBJS =$(addprefix $(OBJDIR)/,rt-error.o rt-get_cpu.o rt-sched.o rt-utils.o)
+LIBOBJS =$(addprefix $(OBJDIR)/,rt-error.o rt-get_cpu.o rt-sched.o rt-utils.o \
+ histogram.o)
$(OBJDIR)/librttest.a: $(LIBOBJS)
$(AR) rcs $@ $^
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 93ce201e9fca..6169170fc66d 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -35,6 +35,7 @@
#include "rt-utils.h"
#include "rt-numa.h"
#include "rt-error.h"
+#include "histogram.h"
#include <bionic.h>
@@ -133,16 +134,13 @@ struct thread_stat {
double avg;
long *values;
long *smis;
- long *hist_array;
- long *outliers;
+ struct histogram *hist;
pthread_t thread;
int threadstarted;
int tid;
long reduce;
long redmax;
long cycleofmax;
- long hist_overflow;
- long num_outliers;
unsigned long smi_count;
};
@@ -216,6 +214,7 @@ static char jsonfile[MAX_PATH];
static struct thread_param **parameters;
static struct thread_stat **statistics;
+static struct histoset hset;
static void print_stat(FILE *fp, struct thread_param *par, int index, int verbose, int quiet);
static void rstat_print_stat(struct thread_param *par, int index, int verbose, int quiet);
@@ -777,15 +776,8 @@ static void *timerthread(void *param)
}
/* Update the histogram */
- if (histogram) {
- if (diff >= histogram) {
- stat->hist_overflow++;
- if (stat->num_outliers < histogram)
- stat->outliers[stat->num_outliers++] = stat->cycles;
- } else {
- stat->hist_array[diff]++;
- }
- }
+ if (histogram)
+ hist_sample(stat->hist, diff);
stat->cycles++;
@@ -1422,19 +1414,13 @@ static void print_hist(struct thread_param *par[], int nthreads)
fprintf(fd, "# Histogram\n");
for (i = 0; i < histogram; i++) {
- unsigned long long int allthreads = 0;
+ unsigned long flags = 0;
fprintf(fd, "%06d ", i);
- for (j = 0; j < nthreads; j++) {
- unsigned long curr_latency=par[j]->stats->hist_array[i];
- fprintf(fd, "%06lu", curr_latency);
- if (j < nthreads - 1)
- fprintf(fd, "\t");
- allthreads += curr_latency;
- }
- if (histofall && nthreads > 1)
- fprintf(fd, "\t%06llu", allthreads);
+ if (histofall)
+ flags |= HSET_PRINT_SUM;
+ hset_print_bucket(&hset, fd, i, flags);
fprintf(fd, "\n");
}
fprintf(fd, "# Min Latencies:");
@@ -1459,8 +1445,8 @@ static void print_hist(struct thread_param *par[], int nthreads)
fprintf(fd, "# Histogram Overflows:");
alloverflows = 0;
for (j = 0; j < nthreads; j++) {
- fprintf(fd, " %05lu", par[j]->stats->hist_overflow);
- alloverflows += par[j]->stats->hist_overflow;
+ fprintf(fd, " %05lu", par[j]->stats->hist->oflow_count);
+ alloverflows += par[j]->stats->hist->oflow_count;
}
if (histofall && nthreads > 1)
fprintf(fd, " %05lu", alloverflows);
@@ -1468,11 +1454,8 @@ static void print_hist(struct thread_param *par[], int nthreads)
fprintf(fd, "# Histogram Overflow at cycle number:\n");
for (i = 0; i < nthreads; i++) {
- fprintf(fd, "# Thread %d:", i);
- for (j = 0; j < par[i]->stats->num_outliers; j++)
- fprintf(fd, " %05lu", par[i]->stats->outliers[j]);
- if (par[i]->stats->num_outliers < par[i]->stats->hist_overflow)
- fprintf(fd, " # %05lu others", par[i]->stats->hist_overflow - par[i]->stats->num_outliers);
+ fprintf(fd, "# Thread %d: ", i);
+ hist_print_oflows(par[i]->stats->hist, fd);
fprintf(fd, "\n");
}
if (smi) {
@@ -1788,8 +1771,7 @@ rstat_err:
static void write_stats(FILE *f, void *data __attribute__ ((unused)))
{
struct thread_param **par = parameters;
- int i, j;
- unsigned comma;
+ int i;
struct thread_stat *s;
fprintf(f, " \"num_threads\": %d,\n", num_threads);
@@ -1800,15 +1782,7 @@ static void write_stats(FILE *f, void *data __attribute__ ((unused)))
fprintf(f, " \"histogram\": {");
s = par[i]->stats;
- for (j = 0, comma = 0; j < histogram; j++) {
- if (s->hist_array[j] == 0)
- continue;
- fprintf(f, "%s", comma ? ",\n" : "\n");
- fprintf(f, " \"%u\": %ld", j, s->hist_array[j]);
- comma = 1;
- }
- if (comma)
- fprintf(f, "\n");
+ hist_print_json(par[i]->stats->hist, f);
fprintf(f, " },\n");
fprintf(f, " \"cycles\": %ld,\n", s->cycles);
fprintf(f, " \"min\": %ld,\n", s->min);
@@ -1991,6 +1965,10 @@ int main(int argc, char **argv)
/* Set-up shm */
rstat_setup();
+ if (histogram && hset_init(&hset, num_threads, 1, histogram, histogram))
+ fatal("failed to allocate histogram of size %d for %d threads\n",
+ histogram, num_threads);
+
parameters = calloc(num_threads, sizeof(struct thread_param *));
if (!parameters)
goto out;
@@ -2066,18 +2044,8 @@ int main(int argc, char **argv)
fatal("error allocating thread status struct for thread %d\n", i);
memset(stat, 0, sizeof(struct thread_stat));
- /* allocate the histogram if requested */
- if (histogram) {
- int bufsize = histogram * sizeof(long);
-
- stat->hist_array = threadalloc(bufsize, node);
- 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 (histogram)
+ stat->hist = &hset.histos[i];
if (verbose) {
int bufsize = VALBUF_SIZE * sizeof(long);
@@ -2215,13 +2183,8 @@ int main(int argc, char **argv)
if (trigger)
trigger_print();
- if (histogram) {
+ if (histogram)
print_hist(parameters, num_threads);
- 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) {
print_tids(parameters, num_threads);
@@ -2263,5 +2226,6 @@ int main(int argc, char **argv)
if (rstat_fd >= 0)
shm_unlink(shm_name);
+ hset_destroy(&hset);
exit(ret);
}
diff --git a/src/include/histogram.h b/src/include/histogram.h
new file mode 100644
index 000000000000..c7aba68ffb99
--- /dev/null
+++ b/src/include/histogram.h
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <stdint.h>
+#include <stdio.h>
+
+struct histogram {
+ unsigned long *buckets;
+ unsigned long width; // interval covered by one bucket
+ unsigned long num; // number of buckets
+ unsigned long events; // number of events logged
+
+ unsigned long *oflows; // events when overflow happened
+ unsigned long oflow_bufsize; // number of overflows that can be logged
+ unsigned long oflow_count; // number of events that overflowed
+ uint64_t oflow_magnitude; // sum of how many buckets overflowed by
+};
+
+struct histoset {
+ struct histogram *histos; // Group of related histograms (e.g. per cpu)
+ struct histogram *sum; // Accumulates events from all histos
+ unsigned long num_histos; // Not including sum
+ unsigned long num_buckets;
+};
+
+#define HIST_OVERFLOW 1
+#define HIST_OVERFLOW_MAG 2
+#define HIST_OVERFLOW_LOG 4
+
+int hist_init(struct histogram *h, unsigned long width, unsigned long num);
+int hist_init_oflow(struct histogram *h, unsigned long num);
+void hist_destroy(struct histogram *h);
+int hist_sample(struct histogram *h, uint64_t sample);
+
+#define HSET_PRINT_SUM 1
+#define HSET_PRINT_JSON 2
+
+int hset_init(struct histoset *hs, unsigned long histos, unsigned long bucket_width,
+ unsigned long num_buckets, unsigned long overflow);
+void hset_destroy(struct histoset *hs);
+void hset_print_bucket(struct histoset *hs, FILE *f, unsigned long bucket,
+ unsigned long flags);
+void hist_print_json(struct histogram *h, FILE *f);
+void hist_print_oflows(struct histogram *h, FILE *f);
diff --git a/src/lib/histogram.c b/src/lib/histogram.c
new file mode 100644
index 000000000000..35a9d604da86
--- /dev/null
+++ b/src/lib/histogram.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Latency histograms
+ *
+ * Copyright 2023 Red Hat Inc.
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include "histogram.h"
+
+int hist_init(struct histogram *h, unsigned long width, unsigned long num)
+{
+ memset(h, 0, sizeof(*h));
+ h->width = width;
+ h->num = num;
+
+ h->buckets = calloc(num, sizeof(unsigned long));
+ if (!h->buckets)
+ return -ENOMEM;
+
+ return 0;
+}
+
+int hist_init_oflow(struct histogram *h, unsigned long num)
+{
+ h->oflow_bufsize = num;
+ h->oflows = calloc(num, sizeof(unsigned long));
+ if (!h->oflows)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void hist_destroy(struct histogram *h)
+{
+ free(h->oflows);
+ h->oflows = NULL;
+ free(h->buckets);
+ h->buckets = NULL;
+}
+
+int hist_sample(struct histogram *h, uint64_t sample)
+{
+ unsigned long bucket = sample / h->width;
+ unsigned long extra;
+ unsigned long event = h->events++;
+ int ret;
+
+ if (bucket < h->num) {
+ h->buckets[bucket]++;
+ return 0;
+ }
+
+ ret = HIST_OVERFLOW;
+ extra = bucket - h->num;
+ if (h->oflow_magnitude + extra > h->oflow_magnitude)
+ h->oflow_magnitude += extra;
+ else
+ ret |= HIST_OVERFLOW_MAG;
+
+ if (h->oflows) {
+ if (h->oflow_count < h->oflow_bufsize)
+ h->oflows[h->oflow_count] = event;
+ else
+ ret |= HIST_OVERFLOW_LOG;
+ }
+
+ h->oflow_count++;
+ return ret;
+}
+
+int hset_init(struct histoset *hs, unsigned long num_histos,
+ unsigned long bucket_width, unsigned long num_buckets,
+ unsigned long overflow)
+{
+ unsigned long i;
+
+ if (num_histos == 0)
+ return -EINVAL;
+
+ hs->num_histos = num_histos;
+ hs->num_buckets = num_buckets;
+ hs->histos = calloc(num_histos, sizeof(struct histogram));
+ if (!hs->histos)
+ return -ENOMEM;
+
+ for (i = 0; i < num_histos; i++) {
+ if (hist_init(&hs->histos[i], bucket_width, num_buckets))
+ goto fail;
+ if (overflow && hist_init_oflow(&hs->histos[i], overflow))
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ hset_destroy(hs);
+ return -ENOMEM;
+}
+
+void hset_destroy(struct histoset *hs)
+{
+ unsigned long i;
+
+ if (hs->histos) {
+ for (i = 0; i < hs->num_histos; i++)
+ hist_destroy(&hs->histos[i]);
+ }
+
+ free(hs->histos);
+ hs->histos = NULL;
+}
+
+void hset_print_bucket(struct histoset *hs, FILE *f, unsigned long bucket,
+ unsigned long flags)
+{
+ unsigned long long sum = 0;
+ unsigned long i;
+
+ if (bucket >= hs->num_buckets)
+ return;
+
+ for (i = 0; i < hs->num_histos; i++) {
+ unsigned long val = hs->histos[i].buckets[bucket];
+
+ sum += val;
+ if (i != 0)
+ fprintf(f, "\t");
+ fprintf(f, "%06lu", val);
+ }
+
+ if (flags & HSET_PRINT_SUM)
+ fprintf(f, "\t%06llu", sum);
+}
+
+void hist_print_json(struct histogram *h, FILE *f)
+{
+ unsigned long i;
+ bool comma = false;
+
+ for (i = 0; i < h->num; i++) {
+ unsigned long val = h->buckets[i];
+
+ if (val != 0) {
+ if (comma)
+ fprintf(f, ",");
+ fprintf(f, "\n \"%lu\": %lu", i, val);
+ comma = true;
+ }
+ }
+
+ fprintf(f, "\n");
+}
+
+void hist_print_oflows(struct histogram *h, FILE *f)
+{
+ unsigned long i;
+
+ for (i = 0; i < h->oflow_count; i++) {
+ if (i >= h->oflow_bufsize)
+ break;
+ if (i != 0)
+ fprintf(f, " ");
+ fprintf(f, "%05lu", h->oflows[i]);
+ }
+
+ if (i >= h->oflow_bufsize)
+ fprintf(f, " # %05lu others", h->oflow_count - h->oflow_bufsize);
+}
--
2.43.0
