[PATCH v9 3/9] benchtests: Add arc4random benchtest
Adhemerval Zanella
adhemerval.zanella@linaro.org
Wed Jul 13 17:36:51 GMT 2022
From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
It shows both throughput (total bytes obtained in the test duration)
and latecy for both arc4random and arc4random_buf with different
sizes.
Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.
---
benchtests/Makefile | 5 +-
benchtests/bench-arc4random.c | 218 +++++++++++++++++++++++++++
benchtests/bench-hash-funcs-kernel.h | 1 +
benchtests/bench-hash-funcs.c | 2 -
benchtests/bench-util.h | 7 +
5 files changed, 230 insertions(+), 3 deletions(-)
create mode 100644 benchtests/bench-arc4random.c
diff --git a/benchtests/Makefile b/benchtests/Makefile
index c279041e19..d99771be74 100644
--- a/benchtests/Makefile
+++ b/benchtests/Makefile
@@ -233,7 +233,10 @@ hash-benchset := \
nss-hash \
# hash-benchset
-stdlib-benchset := strtod
+stdlib-benchset := \
+ arc4random \
+ strtod \
+ # stdlib-benchset
stdio-common-benchset := sprintf
diff --git a/benchtests/bench-arc4random.c b/benchtests/bench-arc4random.c
new file mode 100644
index 0000000000..d8fd40298e
--- /dev/null
+++ b/benchtests/bench-arc4random.c
@@ -0,0 +1,218 @@
+/* arc4random benchmarks.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include "bench-timing.h"
+#include "bench-util.h"
+#include "json-lib.h"
+#include <array_length.h>
+#include <intprops.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/support.h>
+#include <support/timespec.h>
+#include <support/xthread.h>
+
+static volatile sig_atomic_t timer_finished;
+
+static void timer_callback (int unused)
+{
+ timer_finished = 1;
+}
+
+static timer_t timer;
+
+/* Run for approximately DURATION seconds, and it does not matter who
+ receive the signal (so not need to mask it on main thread). */
+static void
+timer_start (void)
+{
+ timer_finished = 0;
+ timer = support_create_timer (DURATION, 0, false, timer_callback);
+}
+static void
+timer_stop (void)
+{
+ support_delete_timer (timer);
+}
+
+static const uint32_t sizes[] = { 0, 16, 32, 48, 64, 80, 96, 112, 128 };
+
+static double
+bench_throughput (void)
+{
+ uint64_t n = 0;
+
+ struct timespec start, end;
+ clock_gettime (CLOCK_MONOTONIC, &start);
+ while (1)
+ {
+ DO_NOT_OPTIMIZE_OUT (arc4random ());
+ n++;
+
+ if (timer_finished == 1)
+ break;
+ }
+ clock_gettime (CLOCK_MONOTONIC, &end);
+ struct timespec diff = timespec_sub (end, start);
+
+ double total = (double) n * sizeof (uint32_t);
+ double duration = (double) diff.tv_sec
+ + (double) diff.tv_nsec / TIMESPEC_HZ;
+
+ return total / duration;
+}
+
+static double
+bench_latency (void)
+{
+ timing_t start, stop, cur;
+ const size_t iters = 1024;
+
+ TIMING_NOW (start);
+ for (size_t i = 0; i < iters; i++)
+ DO_NOT_OPTIMIZE_OUT (arc4random ());
+ TIMING_NOW (stop);
+
+ TIMING_DIFF (cur, start, stop);
+
+ return (double) (cur) / (double) iters;
+}
+
+static double
+bench_buf_throughput (size_t len)
+{
+ uint8_t buf[len];
+ uint64_t n = 0;
+
+ struct timespec start, end;
+ clock_gettime (CLOCK_MONOTONIC, &start);
+ while (1)
+ {
+ arc4random_buf (buf, len);
+ n++;
+
+ if (timer_finished == 1)
+ break;
+ }
+ clock_gettime (CLOCK_MONOTONIC, &end);
+ struct timespec diff = timespec_sub (end, start);
+
+ double total = (double) n * len;
+ double duration = (double) diff.tv_sec
+ + (double) diff.tv_nsec / TIMESPEC_HZ;
+
+ return total / duration;
+}
+
+static double
+bench_buf_latency (size_t len)
+{
+ timing_t start, stop, cur;
+ const size_t iters = 1024;
+
+ uint8_t buf[len];
+
+ TIMING_NOW (start);
+ for (size_t i = 0; i < iters; i++)
+ arc4random_buf (buf, len);
+ TIMING_NOW (stop);
+
+ TIMING_DIFF (cur, start, stop);
+
+ return (double) (cur) / (double) iters;
+}
+
+static void
+bench_singlethread (json_ctx_t *json_ctx)
+{
+ json_element_object_begin (json_ctx);
+
+ json_array_begin (json_ctx, "throughput");
+ for (int i = 0; i < array_length (sizes); i++)
+ {
+ timer_start ();
+ double r = sizes[i] == 0
+ ? bench_throughput () : bench_buf_throughput (sizes[i]);
+ timer_stop ();
+
+ json_element_double (json_ctx, r);
+ }
+ json_array_end (json_ctx);
+
+ json_array_begin (json_ctx, "latency");
+ for (int i = 0; i < array_length (sizes); i++)
+ {
+ timer_start ();
+ double r = sizes[i] == 0
+ ? bench_latency () : bench_buf_latency (sizes[i]);
+ timer_stop ();
+
+ json_element_double (json_ctx, r);
+ }
+ json_array_end (json_ctx);
+
+ json_element_object_end (json_ctx);
+}
+
+static void
+run_bench (json_ctx_t *json_ctx, const char *name,
+ char *const*fnames, size_t fnameslen,
+ void (*bench) (json_ctx_t *ctx))
+{
+ json_attr_object_begin (json_ctx, name);
+ json_array_begin (json_ctx, "functions");
+ for (int i = 0; i < fnameslen; i++)
+ json_element_string (json_ctx, fnames[i]);
+ json_array_end (json_ctx);
+
+ json_array_begin (json_ctx, "results");
+ bench (json_ctx);
+ json_array_end (json_ctx);
+ json_attr_object_end (json_ctx);
+}
+
+static int
+do_test (void)
+{
+ char *fnames[array_length (sizes)];
+ for (int i = 0; i < array_length (sizes); i++)
+ if (sizes[i] == 0)
+ fnames[i] = xasprintf ("arc4random");
+ else
+ fnames[i] = xasprintf ("arc4random_buf(%u)", sizes[i]);
+
+ json_ctx_t json_ctx;
+ json_init (&json_ctx, 0, stdout);
+
+ json_document_begin (&json_ctx);
+ json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
+
+ run_bench (&json_ctx, "single-thread", fnames, array_length (fnames),
+ bench_singlethread);
+
+ json_document_end (&json_ctx);
+
+ for (int i = 0; i < array_length (sizes); i++)
+ free (fnames[i]);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/benchtests/bench-hash-funcs-kernel.h b/benchtests/bench-hash-funcs-kernel.h
index 83995cc0ae..63034f7e44 100644
--- a/benchtests/bench-hash-funcs-kernel.h
+++ b/benchtests/bench-hash-funcs-kernel.h
@@ -17,6 +17,7 @@
<https://www.gnu.org/licenses/>. */
+#include "bench-util.h"
/* We go through the trouble of using macros here because many of the
hash functions are meant to be inlined so its not fair to benchmark
diff --git a/benchtests/bench-hash-funcs.c b/benchtests/bench-hash-funcs.c
index 578c5cbae2..44b349d30c 100644
--- a/benchtests/bench-hash-funcs.c
+++ b/benchtests/bench-hash-funcs.c
@@ -38,8 +38,6 @@
#include <stdlib.h>
#include <string.h>
-#define DO_NOT_OPTIMIZE_OUT(x) __asm__ volatile("" : : "r,m"(x) : "memory")
-
enum
{
NFIXED_ITERS = 1048576,
diff --git a/benchtests/bench-util.h b/benchtests/bench-util.h
index d0e29423aa..00f78d649f 100644
--- a/benchtests/bench-util.h
+++ b/benchtests/bench-util.h
@@ -16,6 +16,13 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+/* Prevent compiler to optimize away call. */
+#define DO_NOT_OPTIMIZE_OUT(value) \
+ ({ \
+ __typeof (value) __v = (value); \
+ asm volatile ("" : : "r,m" (__v) : "memory"); \
+ __v; \
+ })
#ifndef START_ITER
# define START_ITER (100000000)
--
2.34.1
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