static int __get_next_rand_offset(struct thread_data *td, struct fio_file *f,
enum fio_ddir ddir, uint64_t *b)
{
uint64_t r, lastb;
lastb = last_block(td, f, ddir);
if (!lastb)
return 1;
if (td->o.random_generator == FIO_RAND_GEN_TAUSWORTHE) {
uint64_t rmax;
rmax = td->o.use_os_rand ? OS_RAND_MAX : FRAND_MAX;
if (td->o.use_os_rand) {
rmax = OS_RAND_MAX;
r = os_random_long(&td->random_state);
} else {
rmax = FRAND_MAX;
r = __rand(&td->__random_state);
}
dprint(FD_RANDOM, "off rand %llu\n", (unsigned long long) r);
*b = (lastb - 1) * (r / ((uint64_t) rmax + 1.0));
} else {
uint64_t off = 0;
if (lfsr_next(&f->lfsr, &off, lastb))
return 1;
*b = off;
}
/*
* if we are not maintaining a random map, we are done.
*/
if (!file_randommap(td, f))
goto ret;
/*
* calculate map offset and check if it's free
*/
if (random_map_free(f, *b))
goto ret;
dprint(FD_RANDOM, "get_next_rand_offset: offset %llu busy\n",
(unsigned long long) *b);
*b = axmap_next_free(f->io_axmap, *b);
if (*b == (uint64_t) -1ULL)
return 1;
ret:
return 0;
}
static int __get_next_rand_offset(struct thread_data *td, struct fio_file *f,
enum fio_ddir ddir, uint64_t *b)
{
uint64_t r;
if (td->o.random_generator == FIO_RAND_GEN_TAUSWORTHE ||
td->o.random_generator == FIO_RAND_GEN_TAUSWORTHE64) {
uint64_t frand_max, lastb;
lastb = last_block(td, f, ddir);
if (!lastb)
return 1;
frand_max = rand_max(&td->random_state);
r = __rand(&td->random_state);
dprint(FD_RANDOM, "off rand %llu\n", (unsigned long long) r);
*b = lastb * (r / ((uint64_t) frand_max + 1.0));
} else {
uint64_t off = 0;
assert(fio_file_lfsr(f));
if (lfsr_next(&f->lfsr, &off))
return 1;
*b = off;
}
/*
* if we are not maintaining a random map, we are done.
*/
if (!file_randommap(td, f))
goto ret;
/*
* calculate map offset and check if it's free
*/
if (random_map_free(f, *b))
goto ret;
dprint(FD_RANDOM, "get_next_rand_offset: offset %llu busy\n",
(unsigned long long) *b);
*b = axmap_next_free(f->io_axmap, *b);
if (*b == (uint64_t) -1ULL)
return 1;
ret:
return 0;
}
int main(int argc, char *argv[])
{
struct fio_lfsr lfsr;
size_t size = (1UL << 28) - 200;
struct axmap *map;
if (argc > 1)
size = strtoul(argv[1], NULL, 10);
printf("Using %llu entries\n", (unsigned long long) size);
lfsr_init(&lfsr, size);
map = axmap_new(size);
while (size--) {
uint64_t val;
lfsr_next(&lfsr, &val);
axmap_set(map, val);
}
return 0;
}
int main(int argc, char *argv[])
{
int r;
struct timeval start, end;
struct fio_lfsr *fl;
int verify = 0;
unsigned int spin = 0;
uint64_t seed = 0;
uint64_t numbers;
uint64_t v_size;
uint64_t i;
void *v = NULL, *v_start;
double total, mean;
/* Read arguments */
switch (argc) {
case 5: if (strncmp(argv[4], "verify", 7) == 0)
verify = 1;
case 4: spin = atoi(argv[3]);
case 3: seed = atol(argv[2]);
case 2: numbers = strtol(argv[1], NULL, 16);
break;
default: usage();
return 1;
}
/* Initialize LFSR */
fl = malloc(sizeof(struct fio_lfsr));
if (!fl) {
perror("malloc");
return 1;
}
r = lfsr_init(fl, numbers, seed, spin);
if (r) {
printf("Initialization failed.\n");
return r;
}
/* Print specs */
printf("LFSR specs\n");
printf("==========================\n");
printf("Size is %u\n", 64 - __builtin_clzl(fl->cached_bit));
printf("Max val is %lu\n", (unsigned long) fl->max_val);
printf("XOR-mask is 0x%lX\n", (unsigned long) fl->xormask);
printf("Seed is %lu\n", (unsigned long) fl->last_val);
printf("Spin is %u\n", fl->spin);
printf("Cycle length is %lu\n", (unsigned long) fl->cycle_length);
/* Create verification table */
if (verify) {
v_size = numbers * sizeof(uint8_t);
v = malloc(v_size);
memset(v, 0, v_size);
printf("\nVerification table is %lf KBs\n", (double)(v_size) / 1024);
}
v_start = v;
/*
* Iterate over a tight loop until we have produced all the requested
* numbers. Verifying the results should introduce some small yet not
* negligible overhead.
*/
fprintf(stderr, "\nTest initiated... ");
fio_gettime(&start, NULL);
while (!lfsr_next(fl, &i)) {
if (verify)
*(uint8_t *)(v + i) += 1;
}
fio_gettime(&end, NULL);
fprintf(stderr, "finished.\n");
/* Check if all expected numbers within range have been calculated */
r = 0;
if (verify) {
fprintf(stderr, "Verifying results... ");
for (i = 0; i < numbers; i++) {
if (*(uint8_t *)(v + i) != 1) {
fprintf(stderr, "failed (%lu = %d).\n",
(unsigned long) i,
*(uint8_t *)(v + i));
r = 1;
break;
}
}
if (!r)
fprintf(stderr, "OK!\n");
}
/* Calculate elapsed time and mean time per number */
total = utime_since(&start, &end);
mean = total / fl->num_vals;
printf("\nTime results ");
if (verify)
printf("(slower due to verification)");
printf("\n==============================\n");
printf("Elapsed: %lf s\n", total / pow(10,6));
printf("Mean: %lf us\n", mean);
free(v_start);
free(fl);
return r;
}
