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tests: benchmark crypto with fixed data size, not time period

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Currently the crypto benchmarks are processing data in varying chunk
sizes, over a fixed time period. This turns out to be a terrible idea
because with small chunk sizes the overhead of checking the elapsed
time on each loop iteration masks the true performance.

Benchmarking over a fixed data size avoids the loop running any system
calls which can interfere with the performance measurements.

Before this change

Enc chunk 512 bytes 2283.47 MB/sec Dec chunk 512 bytes 2236.23 MB/sec OK
Enc chunk 4096 bytes 2744.97 MB/sec Dec chunk 4096 bytes 2614.71 MB/sec OK
Enc chunk 16384 bytes 2777.53 MB/sec Dec chunk 16384 bytes 2678.44 MB/sec OK
Enc chunk 65536 bytes 2809.34 MB/sec Dec chunk 65536 bytes 2699.47 MB/sec OK

After this change

Enc chunk 512 bytes 2058.22 MB/sec Dec chunk 512 bytes 2030.11 MB/sec OK
Enc chunk 4096 bytes 2699.27 MB/sec Dec chunk 4096 bytes 2573.78 MB/sec OK
Enc chunk 16384 bytes 2748.52 MB/sec Dec chunk 16384 bytes 2653.76 MB/sec OK
Enc chunk 65536 bytes 2814.08 MB/sec Dec chunk 65536 bytes 2712.74 MB/sec OK

The actual crypto performance hasn't changed, which shows how
significant the mis-measurement has been for small data sizes.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Chen Qun 2019-10-17 14:22:19 +01:00
parent 460316109f
commit f55d31032c
1 changed files with 150 additions and 0 deletions
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150
tests-benchmark-crypto-with-fixed-data-size-not-time.patch Normal file
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@ -0,0 +1,150 @@
From c151519a7f5c08dde9a32534bc485588a5793967 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Thu, 17 Oct 2019 14:22:19 +0100
Subject: [PATCH] tests: benchmark crypto with fixed data size, not time period
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Currently the crypto benchmarks are processing data in varying chunk
sizes, over a fixed time period. This turns out to be a terrible idea
because with small chunk sizes the overhead of checking the elapsed
time on each loop iteration masks the true performance.
Benchmarking over a fixed data size avoids the loop running any system
calls which can interfere with the performance measurements.
Before this change
Enc chunk 512 bytes 2283.47 MB/sec Dec chunk 512 bytes 2236.23 MB/sec OK
Enc chunk 4096 bytes 2744.97 MB/sec Dec chunk 4096 bytes 2614.71 MB/sec OK
Enc chunk 16384 bytes 2777.53 MB/sec Dec chunk 16384 bytes 2678.44 MB/sec OK
Enc chunk 65536 bytes 2809.34 MB/sec Dec chunk 65536 bytes 2699.47 MB/sec OK
After this change
Enc chunk 512 bytes 2058.22 MB/sec Dec chunk 512 bytes 2030.11 MB/sec OK
Enc chunk 4096 bytes 2699.27 MB/sec Dec chunk 4096 bytes 2573.78 MB/sec OK
Enc chunk 16384 bytes 2748.52 MB/sec Dec chunk 16384 bytes 2653.76 MB/sec OK
Enc chunk 65536 bytes 2814.08 MB/sec Dec chunk 65536 bytes 2712.74 MB/sec OK
The actual crypto performance hasn't changed, which shows how
significant the mis-measurement has been for small data sizes.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
tests/benchmark-crypto-cipher.c | 26 ++++++++++++++------------
tests/benchmark-crypto-hash.c | 17 +++++++++--------
2 files changed, 23 insertions(+), 20 deletions(-)
diff --git a/tests/benchmark-crypto-cipher.c b/tests/benchmark-crypto-cipher.c
index 67fdf8c31d..cb6b7200a5 100644
--- a/tests/benchmark-crypto-cipher.c
+++ b/tests/benchmark-crypto-cipher.c
@@ -21,11 +21,12 @@ static void test_cipher_speed(size_t chunk_size,
{
QCryptoCipher *cipher;
Error *err = NULL;
- double total = 0.0;
uint8_t *key = NULL, *iv = NULL;
uint8_t *plaintext = NULL, *ciphertext = NULL;
size_t nkey;
size_t niv;
+ const size_t total = 2 * GiB;
+ size_t remain;
if (!qcrypto_cipher_supports(alg, mode)) {
return;
@@ -58,33 +59,34 @@ static void test_cipher_speed(size_t chunk_size,
&err) == 0);
g_test_timer_start();
- do {
+ remain = total;
+ while (remain) {
g_assert(qcrypto_cipher_encrypt(cipher,
plaintext,
ciphertext,
chunk_size,
&err) == 0);
- total += chunk_size;
- } while (g_test_timer_elapsed() < 1.0);
+ remain -= chunk_size;
+ }
+ g_test_timer_elapsed();
- total /= MiB;
g_print("Enc chunk %zu bytes ", chunk_size);
- g_print("%.2f MB/sec ", total / g_test_timer_last());
+ g_print("%.2f MB/sec ", (double)total / MiB / g_test_timer_last());
- total = 0.0;
g_test_timer_start();
- do {
+ remain = total;
+ while (remain) {
g_assert(qcrypto_cipher_decrypt(cipher,
plaintext,
ciphertext,
chunk_size,
&err) == 0);
- total += chunk_size;
- } while (g_test_timer_elapsed() < 1.0);
+ remain -= chunk_size;
+ }
+ g_test_timer_elapsed();
- total /= MiB;
g_print("Dec chunk %zu bytes ", chunk_size);
- g_print("%.2f MB/sec ", total / g_test_timer_last());
+ g_print("%.2f MB/sec ", (double)total / MiB / g_test_timer_last());
qcrypto_cipher_free(cipher);
g_free(plaintext);
diff --git a/tests/benchmark-crypto-hash.c b/tests/benchmark-crypto-hash.c
index 9b6f7a9155..7f659f7323 100644
--- a/tests/benchmark-crypto-hash.c
+++ b/tests/benchmark-crypto-hash.c
@@ -20,7 +20,8 @@ static void test_hash_speed(const void *opaque)
size_t chunk_size = (size_t)opaque;
uint8_t *in = NULL, *out = NULL;
size_t out_len = 0;
- double total = 0.0;
+ const size_t total = 2 * GiB;
+ size_t remain;
struct iovec iov;
int ret;
@@ -31,20 +32,20 @@ static void test_hash_speed(const void *opaque)
iov.iov_len = chunk_size;
g_test_timer_start();
- do {
+ remain = total;
+ while (remain) {
ret = qcrypto_hash_bytesv(QCRYPTO_HASH_ALG_SHA256,
&iov, 1, &out, &out_len,
NULL);
g_assert(ret == 0);
- total += chunk_size;
- } while (g_test_timer_elapsed() < 5.0);
+ remain -= chunk_size;
+ }
+ g_test_timer_elapsed();
- total /= MiB;
g_print("sha256: ");
- g_print("Testing chunk_size %zu bytes ", chunk_size);
- g_print("done: %.2f MB in %.2f secs: ", total, g_test_timer_last());
- g_print("%.2f MB/sec\n", total / g_test_timer_last());
+ g_print("Hash %zu GB chunk size %zu bytes ", total / GiB, chunk_size);
+ g_print("%.2f MB/sec ", (double)total / MiB / g_test_timer_last());
g_free(out);
g_free(in);
--
2.27.0