int drop_cache(const char * path)
{
#ifdef __linux__
struct stat st;
int r = stat(path, &st);
if(r < 0)
{
perror(path);
return r;
}
if(S_ISDIR(st.st_mode))
{
struct dirent * entry;
DIR * dir = opendir(path);
if(!dir)
{
perror(path);
return -1;
}
while((entry = readdir(dir)))
{
char * full = NULL;
if(!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, ".."))
continue;
r = asprintf(&full, "%s/%s", path, entry->d_name);
if(r < 0)
{
perror(entry->d_name);
continue;
}
drop_cache(full);
free(full);
}
closedir(dir);
}
else
{
int fd = open(path, O_RDONLY);
if(fd < 0)
{
perror(path);
return fd;
}
r = posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED);
if(r < 0)
{
perror(path);
return r;
}
close(fd);
}
return 0;
#else
printf("%s(): not supported\n", __FUNCTION__);
return -ENOSYS;
#endif
}
static int filedev_bwrite(struct ext4_blockdev *bdev, const void *buf,
uint64_t blk_id, uint32_t blk_cnt)
{
if (fseek(dev_file, blk_id * bdev->ph_bsize, SEEK_SET))
return EIO;
if (!fwrite(buf, bdev->ph_bsize * blk_cnt, 1, dev_file))
return EIO;
drop_cache();
return EOK;
}
static int
measured_exec(const char *device, char *const *args)
{
struct disk_stats stats0;
struct disk_stats stats1;
char stat_path[PATH_MAX];
uint64_t time0;
uint64_t time1;
uint32_t bytes;
uint32_t milli_io;
float milli_tot;
float seconds;
int status;
pid_t pid;
uint16_t sector_sz;
if (find_device_stat(device, stat_path) == -1)
return -1;
if ((sector_sz = sector_size(device)) == -1) {
fprintf(stderr, "%s: failed to determine sector size: %s\n",
prog, strerror(errno));
return -1;
}
if (drop_cache() == -1)
return -1;
/* collect opening data */
if (read_disk_stats(prog, stat_path, &stats0) == -1)
return -1;
time0 = clock_monotonic();
/* start child */
if ((pid = fork()) == -1) {
fprintf(stderr, "%s: fork failed: %s\n",
prog, strerror(errno));
return -1;
} else if (!pid) {
execvp(*args, args);
fprintf(stderr, "%s: exec failed: %s\n",
prog, strerror(errno));
exit(0xff);
}
/* wait for child */
status = 0;
for (;;) {
if (waitpid(pid, &status, 0) == -1) {
if (errno == EINTR) continue;
fprintf(stderr, "%s: wait failed: %s\n",
prog, strerror(errno));
return -1;
}
break;
}
/* collect closing data */
if (read_disk_stats(prog, stat_path, &stats1) == -1)
return -1;
time1 = clock_monotonic();
/* check for child error */
if (WIFSIGNALED(status)) {
fprintf(stderr, "%s: child terminated by signal %s\n",
prog, signame(WTERMSIG(status)));
return -1;
} else if (WEXITSTATUS(status)) {
if (WEXITSTATUS(status) != 0xff)
fprintf(stderr, "%s: child exited with %d\n",
prog, WEXITSTATUS(status));
return -1;
}
/* process data */
bytes = ((stats1.sectors_read + stats1.sectors_written) -
(stats0.sectors_read + stats0.sectors_written)) * sector_sz;
milli_io = stats1.milli_io - stats0.milli_io;
milli_tot = (time1 - time0) / 1000000.0f;
seconds = (time1 - time0) / 1000000000.0f;
/* print data */
printf("RATE_KBPS\t%.10e\n", bytes / (seconds * 1024));
printf("RATE_MBPS\t%.10e\n", bytes / (seconds * 1048576));
printf("TIME_S\t\t%.10e\n", seconds);
printf("UTIL\t\t%.10e\n", milli_io / milli_tot);
return 0;
}