From: Robert Elliott <elliott@xxxxxxx>
Run memcpy tests over much larger sizes (L3 cache size and larger),
and reduce the number of iterations.
---
lib/memcpy.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 78 insertions(+), 10 deletions(-)
diff --git a/lib/memcpy.c b/lib/memcpy.c
index 00e65aa7..a79d7c50 100644
--- a/lib/memcpy.c
+++ b/lib/memcpy.c
@@ -8,9 +8,17 @@
#include "../gettime.h"
#include "../fio.h"
-#define BUF_SIZE 32 * 1024 * 1024ULL
+/* largest last-level CPU cache size of an x86 in 2018 in bytes */
+#define LLC_SIZE (45* 1024 * 1024ULL)
-#define NR_ITERS 64
+#define BUF_SIZE (LLC_SIZE * 4ULL)
+
+/* alignment in bytes for the buffers. Ensure that functions like
+ * libc memcpy can use most optimal paths (512 B for x86_64 AVX2).
+ */
+#define BUF_ALIGN 512
+
+#define NR_ITERS 8
struct memcpy_test {
const char *name;
@@ -21,15 +29,27 @@ struct memcpy_test {
static struct memcpy_test tests[] = {
{
- .name = "8 bytes",
+ .name = " 4 bytes",
+ .size = 4,
+ },
+ {
+ .name = " 8 bytes",
.size = 8,
},
{
- .name = "16 bytes",
+ .name = " 16 bytes",
.size = 16,
},
{
- .name = "96 bytes",
+ .name = " 32 bytes",
+ .size = 32,
+ },
+ {
+ .name = " 64 bytes",
+ .size = 64,
+ },
+ {
+ .name = " 96 bytes",
.size = 96,
},
{
@@ -45,25 +65,73 @@ static struct memcpy_test tests[] = {
.size = 512,
},
{
- .name = "2048 bytes",
+ .name = " 2 KiB",
.size = 2048,
},
{
- .name = "8192 bytes",
+ .name = " 4 KiB",
+ .size = 4096,
+ },
+ {
+ .name = " 8 KiB",
.size = 8192,
},
{
- .name = "131072 bytes",
+ .name = "128 KiB",
.size = 131072,
},
{
- .name = "262144 bytes",
+ .name = "256 KiB",
.size = 262144,
},
{
- .name = "524288 bytes",
+ .name = "512 KiB",
.size = 524288,
},
+ {
+ .name = " 8 MiB",
+ .size = 8 * 1024 * 1024,
+ },
+ {
+ .name = "6x 1.375 MiB",
+ .size = 8650752,
+ },
+ {
+ .name = " 9 MiB",
+ .size = 9 * 1024 * 1024,
+ },
+ {
+ .name = " 16 MiB",
+ .size = 16 * 1024 * 1024, /* 3/4 L3 size is 16.5 */
+ },
+ {
+ .name = " 17 MiB",
+ .size = 17 * 1024 * 1024, /* 3/4 L3 size is 16.5 */
+ },
+ {
+ .name = " 22 MiB",
+ .size = 22 * 1024 * 1024, /* L3 size */
+ },
+ {
+ .name = " 32 MiB",
+ .size = 32 * 1024 * 1024, /* >L3 size */
+ },
+ {
+ .name = " 40 MiB",
+ .size = 40 * 1024 * 1024,
+ },
+ {
+ .name = " 48 MiB",
+ .size = 48 * 1024 * 1024, /* larger than most L3 */
+ },
+ {
+ .name = "128 MiB",
+ .size = 128 * 1024 * 1024, /* much larger than L3 */
+ },
+ {
+ .name = "full buffer",
+ .size = BUF_SIZE,
+ },
{
.name = NULL,
},
--
2.14.3
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