[PATCH] Benchtests: Improve large memcpy/memset benchmarks

Noah Goldstein goldstein.w.n@gmail.com
Mon Mar 18 19:29:18 GMT 2024


On Mon, Mar 18, 2024 at 10:08 AM Wilco Dijkstra <Wilco.Dijkstra@arm.com> wrote:
>
> Adjust sizes between 64KB and 16MB and iterations based on length.
> Remove incorrect uses of alloc_bufs (since we're not interested in measuring
> Linux clear_page time).
>
> OK for commit?
>
> ---
>
> diff --git a/benchtests/bench-bzero-large.c b/benchtests/bench-bzero-large.c
> index 7076c0a17b00d76c26aa6adb4c3cc0aedcf69955..dea414ec8d1bb160409725996244178ee4fa93fd 100644
> --- a/benchtests/bench-bzero-large.c
> +++ b/benchtests/bench-bzero-large.c
> @@ -22,9 +22,8 @@
>  #else
>  # define TEST_NAME "bzero"
>  #endif
> -#define START_SIZE (128 * 1024)
> -#define MIN_PAGE_SIZE (getpagesize () + 64 * 1024 * 1024)
> -#define TIMEOUT (20 * 60)
> +#define START_SIZE (64 * 1024)
> +#define MIN_PAGE_SIZE (getpagesize () + 16 * 1024 * 1024)
>  #include "bench-string.h"
>
>  #include "json-lib.h"
> @@ -52,7 +51,7 @@ IMPL (memset_zero, 0)
>  static void
>  do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, size_t n)
>  {
> -  size_t i, iters = 16;
> +  size_t i, iters = (MIN_PAGE_SIZE * 64) / n;
>    timing_t start, stop, cur;
>
>    TIMING_NOW (start);
> @@ -74,20 +73,13 @@ do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, size_t n)
>  static void
>  do_test (json_ctx_t *json_ctx, size_t align, size_t len)
>  {
> -  align &= 63;
> -  if ((align + len) * sizeof (CHAR) > page_size)
> -    return;
> -
>    json_element_object_begin (json_ctx);
>    json_attr_uint (json_ctx, "length", len);
>    json_attr_uint (json_ctx, "alignment", align);
>    json_array_begin (json_ctx, "timings");
>
>    FOR_EACH_IMPL (impl, 0)
> -    {
> -      do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, len);
> -      alloc_bufs ();
> -    }
> +    do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, len);
>
>    json_array_end (json_ctx);
>    json_element_object_end (json_ctx);
> diff --git a/benchtests/bench-memcpy-large.c b/benchtests/bench-memcpy-large.c
> index 7b2c5530af3883acc4b3895cb11667e6ff1a55ff..9e544a4729197f886f6cb092ec225004b586d197 100644
> --- a/benchtests/bench-memcpy-large.c
> +++ b/benchtests/bench-memcpy-large.c
> @@ -19,10 +19,9 @@
>  #ifndef MEMCPY_RESULT
>  # define MEMCPY_RESULT(dst, len) dst
>  # define START_SIZE (64 * 1024)
> -# define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
> +# define MIN_PAGE_SIZE (getpagesize () + 16 * 1024 * 1024)
>  # define TEST_MAIN
>  # define TEST_NAME "memcpy"
> -# define TIMEOUT (20 * 60)
>  # include "bench-string.h"
>
>  IMPL (memcpy, 1)
> @@ -36,7 +35,7 @@ static void
>  do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, const char *src,
>              size_t len)
>  {
> -  size_t i, iters = 16;
> +  size_t i, iters = (MIN_PAGE_SIZE * 8) / len;
>    timing_t start, stop, cur;
>
>    TIMING_NOW (start);
> @@ -59,12 +58,7 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
>    char *s1, *s2;
>    size_t repeats;
>    align1 &= 4095;
> -  if (align1 + len >= page_size)
> -    return;
> -
>    align2 &= 4095;
> -  if (align2 + len >= page_size)
> -    return;
>
>    s1 = (char *) (buf1 + align1);
>    s2 = (char *) (buf2 + align2);
> diff --git a/benchtests/bench-memmove-large.c b/benchtests/bench-memmove-large.c
> index a09dd3678848a3bf8612732439700eb8ef5d82ea..fd504653f681b172800cc34e054cc745180aa4fa 100644
> --- a/benchtests/bench-memmove-large.c
> +++ b/benchtests/bench-memmove-large.c
> @@ -16,12 +16,10 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>
> -#define BASE_PAGE_SIZE (1024 * 1024)
> -#define START_SIZE (4 * 1024)
> +#define START_SIZE (64 * 1024)
>  #define MIN_PAGE_SIZE (getpagesize () + 16 * 1024 * 1024)
>  #define TEST_MAIN
>  #define TEST_NAME "memmove"
> -#define TIMEOUT (20 * 60)
>  #include "bench-string.h"
>  #include "json-lib.h"
>
> @@ -33,7 +31,7 @@ static void
>  do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
>              size_t len)
>  {
> -  size_t i, iters = 16;
> +  size_t i, iters = (MIN_PAGE_SIZE * 8) / len;
maybe MAX(16, (MIN_PAGE_SIZE * )/ len). Likewise above.
>    timing_t start, stop, cur;
>
>    TIMING_NOW (start);
> @@ -54,13 +52,8 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len)
>    size_t i, j;
>    char *s1, *s2;
>
> -  align1 &= 127;
> -  if (align1 + len >= page_size)
> -    return;
> -
> -  align2 &= 127;
> -  if (align2 + len >= page_size)
> -    return;
> +  align1 &= 4095;
> +  align2 &= 4095;
>
>    s1 = (char *) (buf2 + align1);
>    s2 = (char *) (buf2 + align2);
> diff --git a/benchtests/bench-memset-large.c b/benchtests/bench-memset-large.c
> index a1f33245d4960c1e82fc441b5faf322204035202..c3f9ee0cd75d3cb30f8b3df15672f895c111fc28 100644
> --- a/benchtests/bench-memset-large.c
> +++ b/benchtests/bench-memset-large.c
> @@ -18,9 +18,8 @@
>
>  #define TEST_MAIN
>  #define TEST_NAME "memset"
> -#define START_SIZE (128 * 1024)
> -#define MIN_PAGE_SIZE (getpagesize () + 64 * 1024 * 1024)
> -#define TIMEOUT (20 * 60)
> +#define START_SIZE (64 * 1024)
> +#define MIN_PAGE_SIZE (getpagesize () + 16 * 1024 * 1024)
>  #include "bench-string.h"
>
>  #include "json-lib.h"
> @@ -35,7 +34,7 @@ static void
>  do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s,
>              int c __attribute ((unused)), size_t n)
>  {
> -  size_t i, iters = 16;
> +  size_t i, iters = (MIN_PAGE_SIZE * 64) / n;
>    timing_t start, stop, cur;
>
>    TIMING_NOW (start);
> @@ -53,10 +52,6 @@ do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s,
>  static void
>  do_test (json_ctx_t *json_ctx, size_t align, int c, size_t len)
>  {
> -  align &= 63;
> -  if ((align + len) * sizeof (CHAR) > page_size)
> -    return;
> -
>    json_element_object_begin (json_ctx);
>    json_attr_uint (json_ctx, "length", len);
>    json_attr_uint (json_ctx, "alignment", align);
> @@ -64,10 +59,7 @@ do_test (json_ctx_t *json_ctx, size_t align, int c, size_t len)
>    json_array_begin (json_ctx, "timings");
>
>    FOR_EACH_IMPL (impl, 0)
> -    {
> -      do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, c, len);
> -      alloc_bufs ();
> -    }
> +    do_one_test (json_ctx, impl, (CHAR *) (buf1) + align, c, len);
>
>    json_array_end (json_ctx);
>    json_element_object_end (json_ctx);
>


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