diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..d944698 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +mybw +*.o diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..dfbba09 --- /dev/null +++ b/Makefile @@ -0,0 +1,13 @@ +OUT := mybw + +CFLAGS := -O2 -Wall -fno-builtin +LDFLAGS := -static -static-libgcc + +SRCS := mybw.c +OBJS := $(SRCS:.c=.o) + +$(OUT): $(OBJS) + $(CC) -o $@ $^ $(LDFLAGS) + +clean: + rm -f $(OUT) $(OBJS) diff --git a/mybw.c b/mybw.c new file mode 100644 index 0000000..fb7a182 --- /dev/null +++ b/mybw.c @@ -0,0 +1,99 @@ +/* + * Copyright (c) 2022, Linaro Ltd. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * 3. Neither the name of the copyright holder nor the names of its contributors + * may be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* gcc -O2 -Wall -fno-builtin -o mybw mybw.c */ + +#include +#include +#include +#include +#include + +#define NSEC_PER_SEC 1000000000UL + +#define TEST_SIZE (50 * 1024ULL*1024*1024) /* 50G */ + +static char *sizestr(uint64_t sz) +{ + static char str[16]; + + if (sz > 1024 * 1024) + snprintf(str, sizeof(str), "%5luM", sz / (1024*1024)); + else if (sz > 1024) + snprintf(str, sizeof(str), "%5luK", sz / 1024); + else + snprintf(str, sizeof(str), "%6lu", sz); + + return str; +} + +static void measure(uint64_t block_size) +{ + struct timespec start; + struct timespec end; + uint64_t block; + uint64_t ts; + void *source; + void *sink; + + if (block_size > TEST_SIZE) + return; + + sink = malloc(block_size); + memset(sink, 0, block_size); + + source = malloc(block_size); + memset(source, 0xcd, block_size); + + clock_gettime(CLOCK_MONOTONIC, &start); + + for (block = 0; block < (TEST_SIZE / block_size); block++) + memcpy(sink, source, block_size); + + clock_gettime(CLOCK_MONOTONIC, &end); + + free(sink); + free(source); + + ts = ((end.tv_sec - start.tv_sec) * NSEC_PER_SEC) + (end.tv_nsec - start.tv_nsec); + + printf("%s: %.02fMB/s\n", sizestr(block_size), (double)TEST_SIZE * 1000 / ts); +} + +int main() +{ + int i; + + for (i = 64; i <= 32 * 1024 * 1024; i <<= 1) + measure(i); + + return 0; +}