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#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <asm/unistd.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mman.h>
#define GB (1024 * 1024 * 1024)
int do_posix_fallocate(char *name, off_t len)
{
int r, fd;
struct timeval tv1, tv2;
unlink(name);
fd = open(name, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
if (fd < 0) {
perror("open");
return -1;
}
printf("posix-fallocate run time:\n");
gettimeofday(&tv1, NULL);
r = posix_fallocate(fd, 0, len);
close(fd);
gettimeofday(&tv2, NULL);
if (r < 0)
return r;
printf("\tseconds:microseconds: %llu:%llu\n", tv1.tv_sec, tv1.tv_usec);
printf("\tseconds:microseconds: %llu:%llu\n", tv2.tv_sec, tv2.tv_usec);
printf("\t(approx %us)\n", tv2.tv_sec - tv1.tv_sec);
return 0;
}
#if 1
int do_fallocate(char *name, off_t len)
{
int r, fd;
struct timeval tv1, tv2;
unlink(name);
fd = open(name, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
if (fd < 0) {
perror("open");
return -1;
}
printf("fallocate run time:\n");
gettimeofday(&tv1, NULL);
r = syscall(__NR_fallocate, fd, 0, len);
close(fd);
gettimeofday(&tv2, NULL);
if (r < 0) {
perror("fallocate");
return r;
}
printf("\tseconds:microseconds: %llu:%llu\n", tv1.tv_sec, tv1.tv_usec);
printf("\tseconds:microseconds: %llu:%llu\n", tv2.tv_sec, tv2.tv_usec);
printf("\t(approx %us)\n", tv2.tv_sec - tv1.tv_sec);
return 0;
}
#endif
int do_mmap(char *name, off_t len)
{
int fd;
struct timeval tv1, tv2;
char *addr;
unlink(name);
fd = open(name, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
if (fd < 0) {
perror("open");
return -1;
}
/* memset has to have the mmap'ed file backed by something on
* disk -- bus error otherwise */
lseek(fd, len - 1, SEEK_SET);
write(fd, "0", 1);
addr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (addr == MAP_FAILED) {
perror("mmap");
return -2;
}
printf("mmap run time:\n");
gettimeofday(&tv1, NULL);
memset(addr, 0, len);
munmap(addr, len);
close(fd);
gettimeofday(&tv2, NULL);
printf("\tseconds:microseconds: %llu:%llu\n", tv1.tv_sec, tv1.tv_usec);
printf("\tseconds:microseconds: %llu:%llu\n", tv2.tv_sec, tv2.tv_usec);
printf("\t(approx %us)\n", tv2.tv_sec - tv1.tv_sec);
return 0;
}
int do_write_chunks(char *name, off_t len, size_t chunk_size)
{
int fd;
struct timeval tv1, tv2;
unsigned long long remain = len;
char *zeros;
zeros = calloc(1, len);
unlink(name);
fd = open(name, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
if (fd < 0) {
perror("open");
return -1;
}
printf("%llu-sized chunk run time:\n", chunk_size);
gettimeofday(&tv1, NULL);
while (remain) {
int bytes = chunk_size;
if (bytes > remain)
bytes = remain;
if ((bytes = write(fd, zeros, bytes)) < 0) {
perror("write");
return -2;
}
remain -= bytes;
}
close(fd);
gettimeofday(&tv2, NULL);
printf("\tseconds:microseconds: %llu:%llu\n", tv1.tv_sec, tv1.tv_usec);
printf("\tseconds:microseconds: %llu:%llu\n", tv2.tv_sec, tv2.tv_usec);
printf("\t(approx %us)\n", tv2.tv_sec - tv1.tv_sec);
free(zeros);
return 0;
}
int main(int argc, char **argv)
{
char *basename;
char *filename;
if (argc < 2) {
printf("usage: %s base-dir\n", argv[0]);
return -1;
}
basename = argv[1];
sprintf(filename, "%s/file-pf", basename);
do_posix_fallocate(filename, 1 * GB);
#if 0
sprintf(filename, "%s/file-pf", basename);
do_fallocate(filename, 1 * GB);
#endif
sprintf(filename, "%s/file-mmap", basename);
do_mmap(filename, 1 * GB);
sprintf(filename, "%s/file-chunk4", basename);
do_write_chunks(filename, 1 * GB, 4 * 1024);
sprintf(filename, "%s/file-chunk8", basename);
do_write_chunks(filename, 1 * GB, 8 * 1024);
return 0;
}
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