Benchtests: Remove broken walk benchmarks

The walk benchmarks don't measure anything useful - memory is not initialized
properly so doing a single walk in 32MB just measures reading the 4KB zero
page for reads and clear_page overhead for writes.  The memset variants don't
even manage to do a walk in the 32MB region due to using incorrect pointer
increments...  Neither is it clear why it is walking backwards since this
won't confuse modern prefetchers.  If you fix the benchmark and print the
bandwidth, the results are identical for all sizes larger than ~1KB since it
is just testing memory bandwidth of a single 32MB block.  This case is already
tested by the large benchmark, so overall it doesn't seem useful to keep these.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Wilco Dijkstra 2024-06-20 11:43:54 +01:00
parent da61ba3f89
commit 5aa2f79691
6 changed files with 0 additions and 581 deletions

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@ -139,7 +139,6 @@ bench-string := \
string-benchset := \
bzero \
bzero-large \
bzero-walk \
memccpy \
memchr \
memcmp \
@ -147,19 +146,15 @@ string-benchset := \
memcpy \
memcpy-large \
memcpy-random \
memcpy-walk \
memmem \
memmove \
memmove-large \
memmove-walk \
mempcpy \
memrchr \
memset \
memset-large \
memset-walk \
memset-zero \
memset-zero-large \
memset-zero-walk \
rawmemchr \
stpcpy \
stpcpy_chk \

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@ -1,143 +0,0 @@
/* Measure memset function throughput with large data sizes.
Copyright (C) 2017-2024 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/>. */
#define TEST_MAIN
#ifdef DO_MEMSET
# define TEST_NAME "memset"
#else
# define TEST_NAME "bzero"
#endif
#define START_SIZE 128
#define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
#define TIMEOUT (20 * 60)
#include "bench-string.h"
#include "json-lib.h"
#ifdef DO_MEMSET
void *generic_memset (void *, int, size_t);
typedef void *(*proto_t) (void *, int, size_t);
IMPL (memset, 1)
IMPL (generic_memset, 0)
#else
static void
memset_zero (void * s, size_t len)
{
memset (s, '\0', len);
}
typedef void (*proto_t) (void *, size_t);
IMPL (bzero, 1)
IMPL (memset_zero, 0)
#endif
static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
size_t n)
{
size_t i, iters = MIN_PAGE_SIZE / n;
timing_t start, stop, cur;
TIMING_NOW (start);
for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
#ifdef DO_MEMSET
CALL (impl, s, 0, n);
#else
CALL (impl, s, n);
#endif
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
json_element_double (json_ctx, (double) cur / i);
}
static void
do_test (json_ctx_t *json_ctx, size_t len)
{
json_element_object_begin (json_ctx);
json_attr_uint (json_ctx, "length", len);
json_array_begin (json_ctx, "timings");
FOR_EACH_IMPL (impl, 0)
{
do_one_test (json_ctx, impl, (CHAR *) buf1,
(CHAR *) buf1 + MIN_PAGE_SIZE - len, len);
alloc_bufs ();
}
json_array_end (json_ctx);
json_element_object_end (json_ctx);
}
int
test_main (void)
{
json_ctx_t json_ctx;
size_t i;
test_init ();
json_init (&json_ctx, 0, stdout);
json_document_begin (&json_ctx);
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
json_attr_object_begin (&json_ctx, "functions");
json_attr_object_begin (&json_ctx, TEST_NAME);
json_attr_string (&json_ctx, "bench-variant", "walk");
json_array_begin (&json_ctx, "ifuncs");
FOR_EACH_IMPL (impl, 0)
json_element_string (&json_ctx, impl->name);
json_array_end (&json_ctx);
json_array_begin (&json_ctx, "results");
for (i = 1; i <= 64; i++)
do_test (&json_ctx, i);
for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
{
do_test (&json_ctx, i);
do_test (&json_ctx, i + 1);
}
json_array_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_document_end (&json_ctx);
return ret;
}
#include <support/test-driver.c>
#ifdef DO_MEMSET
# define libc_hidden_builtin_def(X)
# define libc_hidden_def(X)
# define libc_hidden_weak(X)
# define weak_alias(X,Y)
# undef MEMSET
# define MEMSET generic_memset
# include <string/memset.c>
#endif

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@ -1,131 +0,0 @@
/* Measure memcpy function combined throughput for different alignments.
Copyright (C) 2017-2024 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/>. */
/* This microbenchmark measures the throughput of memcpy for various sizes from
1 byte to 32MiB, doubling every iteration and then misaligning by 0-15
bytes. The copies are done from source to destination and then back and the
source walks forward across the array and the destination walks backward by
one byte each, thus measuring misaligned accesses as well. The idea is to
avoid caching effects by copying a different string and far enough from each
other, walking in different directions so that we can measure prefetcher
efficiency (software or hardware) more closely than with a loop copying the
same data over and over, which eventually only gives us L1 cache
performance. */
#ifndef MEMCPY_RESULT
# define MEMCPY_RESULT(dst, len) dst
# define START_SIZE 128
# define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
# define TEST_MAIN
# define TEST_NAME "memcpy"
# define TIMEOUT (20 * 60)
# include "bench-string.h"
IMPL (memcpy, 1)
#endif
#include "json-lib.h"
typedef char *(*proto_t) (char *, const char *, size_t);
static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
size_t len)
{
size_t i = 0;
timing_t start, stop, cur;
char *dst_end = dst + MIN_PAGE_SIZE - len;
char *src_end = src + MIN_PAGE_SIZE - len;
TIMING_NOW (start);
/* Copy the entire buffer backwards, LEN at a time. */
for (; src_end >= src && dst_end >= dst; src_end -= len, dst_end -= len, i++)
CALL (impl, src_end, dst_end, len);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
json_element_double (json_ctx, (double) cur / i);
}
static void
do_test (json_ctx_t *json_ctx, size_t len, int both_ways)
{
char *s1, *s2;
size_t repeats;
s1 = (char *) (buf1);
s2 = (char *) (buf2);
for (repeats = both_ways ? 2 : 1; repeats; --repeats)
{
json_element_object_begin (json_ctx);
json_attr_uint (json_ctx, "length", (double) len);
json_attr_uint (json_ctx, "dst > src", (double) (s2 > s1));
json_array_begin (json_ctx, "timings");
FOR_EACH_IMPL (impl, 0)
do_one_test (json_ctx, impl, s2, s1, len);
json_array_end (json_ctx);
json_element_object_end (json_ctx);
s1 = (char *) (buf2);
s2 = (char *) (buf1);
}
}
int
test_main (void)
{
json_ctx_t json_ctx;
test_init ();
json_init (&json_ctx, 0, stdout);
json_document_begin (&json_ctx);
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
json_attr_object_begin (&json_ctx, "functions");
json_attr_object_begin (&json_ctx, "memcpy");
json_attr_string (&json_ctx, "bench-variant", "walk");
json_array_begin (&json_ctx, "ifuncs");
FOR_EACH_IMPL (impl, 0)
json_element_string (&json_ctx, impl->name);
json_array_end (&json_ctx);
json_array_begin (&json_ctx, "results");
for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
{
do_test (&json_ctx, i, 1);
do_test (&json_ctx, i + 1, 1);
}
json_array_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_document_end (&json_ctx);
return ret;
}
#include <support/test-driver.c>

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@ -1,160 +0,0 @@
/* Measure memmove function combined throughput for different alignments.
Copyright (C) 2017-2024 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/>. */
/* This microbenchmark measures the throughput of memmove for various sizes from
1 byte to 32MiB, doubling every iteration and then misaligning by 0-15
bytes. The copies are done from source to destination and then back and the
source walks forward across the array and the destination walks backward by
one byte each, thus measuring misaligned accesses as well. The idea is to
avoid caching effects by copying a different string and far enough from each
other, walking in different directions so that we can measure prefetcher
efficiency (software or hardware) more closely than with a loop copying the
same data over and over, which eventually only gives us L1 cache
performance. */
#ifndef MEMMOVE_RESULT
# define MEMMOVE_RESULT(dst, len) dst
# define START_SIZE 128
# define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
# define TEST_MAIN
# define TEST_NAME "memmove"
# define TIMEOUT (20 * 60)
# include "bench-string.h"
#define NO_OVERLAP 0
#define PARTIAL_OVERLAP 1
#define COMPLETE_OVERLAP 2
IMPL (memmove, 1)
#endif
#include "json-lib.h"
typedef char *(*proto_t) (char *, const char *, size_t);
static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
size_t len)
{
size_t i = 0;
timing_t start, stop, cur;
char *dst_end = dst + MIN_PAGE_SIZE - len;
char *src_end = src + MIN_PAGE_SIZE - len;
TIMING_NOW (start);
/* Copy the entire buffer backwards, LEN at a time. */
for (; src_end >= src && dst <= dst_end; dst += len, src_end -= len, i++)
CALL (impl, dst, src_end, len);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
json_element_double (json_ctx, (double) cur / i);
}
static void
do_test (json_ctx_t *json_ctx, size_t len, int overlap, int both_ways)
{
char *s1, *s2, *tmp;
size_t repeats;
s1 = (char *) (buf1);
s2 = (char *) (buf2);
if (overlap != NO_OVERLAP)
s2 = s1;
if (overlap == PARTIAL_OVERLAP)
s2 += len / 2;
for (repeats = both_ways ? 2 : 1; repeats; --repeats)
{
json_element_object_begin (json_ctx);
json_attr_uint (json_ctx, "length", (double) len);
json_attr_string(json_ctx, "overlap",
overlap == NO_OVERLAP ? "none"
: overlap == PARTIAL_OVERLAP ? "partial"
: "complete");
json_attr_uint (json_ctx, "dst > src", (double) (s2 > s1));
json_array_begin (json_ctx, "timings");
FOR_EACH_IMPL (impl, 0)
do_one_test (json_ctx, impl, (char *) buf2, (char *) buf1, len);
json_array_end (json_ctx);
json_element_object_end (json_ctx);
tmp = s1;
s1 = s2;
s2 = tmp;
}
}
int
test_main (void)
{
json_ctx_t json_ctx;
test_init ();
json_init (&json_ctx, 0, stdout);
json_document_begin (&json_ctx);
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
json_attr_object_begin (&json_ctx, "functions");
json_attr_object_begin (&json_ctx, "memmove");
json_attr_string (&json_ctx, "bench-variant", "walk");
json_array_begin (&json_ctx, "ifuncs");
FOR_EACH_IMPL (impl, 0)
json_element_string (&json_ctx, impl->name);
json_array_end (&json_ctx);
json_array_begin (&json_ctx, "results");
/* Non-overlapping buffers. */
for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
{
do_test (&json_ctx, i, NO_OVERLAP, 1);
do_test (&json_ctx, i + 1, NO_OVERLAP, 1);
}
/* Partially-overlapping buffers. */
for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE / 2; i <<= 1)
{
do_test (&json_ctx, i, PARTIAL_OVERLAP, 1);
do_test (&json_ctx, i + 1, PARTIAL_OVERLAP, 1);
}
/* Complete-overlapping buffers. */
for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
{
do_test (&json_ctx, i, COMPLETE_OVERLAP, 0);
do_test (&json_ctx, i + 1, COMPLETE_OVERLAP, 0);
}
json_array_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_document_end (&json_ctx);
return ret;
}
#include <support/test-driver.c>

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@ -1,122 +0,0 @@
/* Measure memset function throughput with large data sizes.
Copyright (C) 2017-2024 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/>. */
#define TEST_MAIN
#define TEST_NAME "memset"
#define START_SIZE 128
#define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
#define TIMEOUT (20 * 60)
#include "bench-string.h"
#include "json-lib.h"
void *generic_memset (void *, int, size_t);
typedef void *(*proto_t) (void *, int, size_t);
IMPL (MEMSET, 1)
IMPL (generic_memset, 0)
static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
int c __attribute ((unused)), size_t n)
{
size_t i, iters = MIN_PAGE_SIZE / n;
timing_t start, stop, cur;
TIMING_NOW (start);
for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
CALL (impl, s, c, n);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
json_element_double (json_ctx, (double) cur / i);
}
static void
do_test (json_ctx_t *json_ctx, int c, size_t len)
{
json_element_object_begin (json_ctx);
json_attr_uint (json_ctx, "length", len);
json_attr_uint (json_ctx, "char", c);
json_array_begin (json_ctx, "timings");
FOR_EACH_IMPL (impl, 0)
{
do_one_test (json_ctx, impl, (CHAR *) buf1,
(CHAR *) buf1 + MIN_PAGE_SIZE - len, c, len);
alloc_bufs ();
}
json_array_end (json_ctx);
json_element_object_end (json_ctx);
}
int
test_main (void)
{
json_ctx_t json_ctx;
size_t i;
test_init ();
json_init (&json_ctx, 0, stdout);
json_document_begin (&json_ctx);
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
json_attr_object_begin (&json_ctx, "functions");
json_attr_object_begin (&json_ctx, TEST_NAME);
json_attr_string (&json_ctx, "bench-variant", "walk");
json_array_begin (&json_ctx, "ifuncs");
FOR_EACH_IMPL (impl, 0)
json_element_string (&json_ctx, impl->name);
json_array_end (&json_ctx);
json_array_begin (&json_ctx, "results");
for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
{
do_test (&json_ctx, 65, i);
do_test (&json_ctx, 65, i + 1);
}
for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
{
do_test (&json_ctx, 0, i);
do_test (&json_ctx, 0, i + 1);
}
json_array_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_attr_object_end (&json_ctx);
json_document_end (&json_ctx);
return ret;
}
#include <support/test-driver.c>
#define libc_hidden_builtin_def(X)
#define libc_hidden_def(X)
#define libc_hidden_weak(X)
#define weak_alias(X,Y)
#undef MEMSET
#define MEMSET generic_memset
#include <string/memset.c>

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@ -1,20 +0,0 @@
/* Measure memset functions for zeroing throughput with large data sizes.
Copyright (C) 2022-2024 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/>. */
#define DO_MEMSET 1
#include "bench-bzero-walk.c"