glibc/benchtests/bench-string.h
Siddhesh Poyarekar 503c92c37a benchtests: Reallocate buffers for memset
Keeping the same buffers along with copying the same size of data into
the same location means that the first routine is typically the
slowest since it has to bear the cost of fetching data into to cache.
Reallocating buffers stabilizes numbers by a bit.

	* benchtests/bench-string.h (realloc_bufs): New function.
	(test_init): Call it.
	* benchtests/bench-memset-large.c (do_test): Likewise.
	* benchtests/bench-memset.c (do_test): Likewise.
2017-09-14 22:54:24 +05:30

237 lines
6.2 KiB
C

/* Measure string and memory functions.
Copyright (C) 2013-2017 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
<http://www.gnu.org/licenses/>. */
#include <getopt.h>
#include <sys/cdefs.h>
typedef struct
{
const char *name;
void (*fn) (void);
long test;
} impl_t;
extern impl_t __start_impls[], __stop_impls[];
#define IMPL(name, test) \
impl_t tst_ ## name \
__attribute__ ((section ("impls"), aligned (sizeof (void *)))) \
= { __STRING (name), (void (*) (void))name, test };
#ifdef TEST_MAIN
# ifndef _GNU_SOURCE
# define _GNU_SOURCE
# endif
# undef __USE_STRING_INLINES
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <sys/mman.h>
# include <sys/param.h>
# include <unistd.h>
# include <fcntl.h>
# include <error.h>
# include <errno.h>
# include <time.h>
# include <ifunc-impl-list.h>
# define GL(x) _##x
# define GLRO(x) _##x
# include "bench-timing.h"
# define TEST_FUNCTION test_main
# ifndef TIMEOUT
# define TIMEOUT (4 * 60)
# endif
# define OPT_ITERATIONS 10000
# define OPT_RANDOM 10001
# define OPT_SEED 10002
# define INNER_LOOP_ITERS 64
unsigned char *buf1, *buf2;
int ret, do_srandom;
unsigned int seed;
size_t page_size;
# ifndef ITERATIONS
size_t iterations = 100000;
# define ITERATIONS_OPTIONS \
{ "iterations", required_argument, NULL, OPT_ITERATIONS },
# define ITERATIONS_PROCESS \
case OPT_ITERATIONS: \
iterations = strtoul (optarg, NULL, 0); \
break;
# define ITERATIONS iterations
# else
# define ITERATIONS_OPTIONS
# define ITERATIONS_PROCESS
# endif
# define CMDLINE_OPTIONS ITERATIONS_OPTIONS \
{ "random", no_argument, NULL, OPT_RANDOM }, \
{ "seed", required_argument, NULL, OPT_SEED },
static void __attribute__ ((used))
cmdline_process_function (int c)
{
switch (c)
{
ITERATIONS_PROCESS
case OPT_RANDOM:
{
int fdr = open ("/dev/urandom", O_RDONLY);
if (fdr < 0 || read (fdr, &seed, sizeof(seed)) != sizeof (seed))
seed = time (NULL);
if (fdr >= 0)
close (fdr);
do_srandom = 1;
break;
}
case OPT_SEED:
seed = strtoul (optarg, NULL, 0);
do_srandom = 1;
break;
}
}
# define CMDLINE_PROCESS cmdline_process_function
# define CALL(impl, ...) \
(* (proto_t) (impl)->fn) (__VA_ARGS__)
# ifdef TEST_NAME
/* Increase size of FUNC_LIST if assert is triggered at run-time. */
static struct libc_ifunc_impl func_list[32];
static int func_count;
static int impl_count = -1;
static impl_t *impl_array;
# define FOR_EACH_IMPL(impl, notall) \
impl_t *impl; \
int count; \
if (impl_count == -1) \
{ \
impl_count = 0; \
if (func_count != 0) \
{ \
int f; \
impl_t *skip = NULL, *a; \
for (impl = __start_impls; impl < __stop_impls; ++impl) \
if (strcmp (impl->name, TEST_NAME) == 0) \
skip = impl; \
else \
impl_count++; \
a = impl_array = malloc ((impl_count + func_count) * \
sizeof (impl_t)); \
for (impl = __start_impls; impl < __stop_impls; ++impl) \
if (impl != skip) \
*a++ = *impl; \
for (f = 0; f < func_count; f++) \
if (func_list[f].usable) \
{ \
a->name = func_list[f].name; \
a->fn = func_list[f].fn; \
a->test = 1; \
a++; \
} \
impl_count = a - impl_array; \
} \
else \
{ \
impl_count = __stop_impls - __start_impls; \
impl_array = __start_impls; \
} \
} \
impl = impl_array; \
for (count = 0; count < impl_count; ++count, ++impl) \
if (!notall || impl->test)
# else /* !TEST_NAME */
# define FOR_EACH_IMPL(impl, notall) \
for (impl_t *impl = __start_impls; impl < __stop_impls; ++impl) \
if (!notall || impl->test)
# endif /* !TEST_NAME */
# ifndef BUF1PAGES
# define BUF1PAGES 1
# endif
static void
alloc_bufs (void)
{
page_size = 2 * getpagesize ();
# ifdef MIN_PAGE_SIZE
if (page_size < MIN_PAGE_SIZE)
page_size = MIN_PAGE_SIZE;
# endif
buf1 = mmap (0, (BUF1PAGES + 1) * page_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (buf1 == MAP_FAILED)
error (EXIT_FAILURE, errno, "mmap failed for buf1");
if (mprotect (buf1 + BUF1PAGES * page_size, page_size, PROT_NONE))
error (EXIT_FAILURE, errno, "mprotect failed for buf1");
buf2 = mmap (0, 2 * page_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (buf2 == MAP_FAILED)
error (EXIT_FAILURE, errno, "mmap failed for buf2");
if (mprotect (buf2 + page_size, page_size, PROT_NONE))
error (EXIT_FAILURE, errno, "mprotect failed for buf2");
}
static void
__attribute__ ((unused))
realloc_bufs (void)
{
int ret = 0;
if (buf1)
ret = munmap (buf1, (BUF1PAGES + 1) * page_size);
if (ret != 0)
error (EXIT_FAILURE, errno, "munmap failed for buf1");
if (buf2)
ret = munmap (buf2, 2 * page_size);
if (ret != 0)
error (EXIT_FAILURE, errno, "munmap failed for buf2");
alloc_bufs ();
}
static void
test_init (void)
{
# ifdef TEST_NAME
func_count = __libc_ifunc_impl_list (TEST_NAME, func_list,
(sizeof func_list
/ sizeof func_list[0]));
# endif
alloc_bufs ();
if (do_srandom)
{
printf ("Setting seed to 0x%x\n", seed);
srandom (seed);
}
}
#endif /* TEST_MAIN */