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, unsigned long long *b)
{
unsigned long long r, lastb;
int loops = 5;
lastb = last_block(td, f, ddir);
if (!lastb)
return 1;
do {
r = os_random_long(&td->random_state);
dprint(FD_RANDOM, "off rand %llu\n", r);
*b = (lastb - 1) * (r / ((unsigned long long) OS_RAND_MAX + 1.0));
/*
* if we are not maintaining a random map, we are done.
*/
if (!file_randommap(td, f))
return 0;
/*
* calculate map offset and check if it's free
*/
if (random_map_free(f, *b))
return 0;
dprint(FD_RANDOM, "get_next_rand_offset: offset %llu busy\n",
*b);
} while (--loops);
/*
* we get here, if we didn't suceed in looking up a block. generate
* a random start offset into the filemap, and find the first free
* block from there.
*/
loops = 10;
do {
f->last_free_lookup = (f->num_maps - 1) *
(r / (OS_RAND_MAX + 1.0));
if (!get_next_free_block(td, f, ddir, b))
return 0;
r = os_random_long(&td->random_state);
} while (--loops);
/*
* that didn't work either, try exhaustive search from the start
*/
f->last_free_lookup = 0;
return get_next_free_block(td, f, ddir, b);
}
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;
}
/*
* Mark a given offset as used in the map.
*/
static void mark_random_map(struct thread_data *td, struct io_u *io_u)
{
unsigned int min_bs = td->o.rw_min_bs;
struct fio_file *f = io_u->file;
unsigned long long block;
unsigned int blocks, nr_blocks;
int busy_check;
block = (io_u->offset - f->file_offset) / (unsigned long long) min_bs;
nr_blocks = (io_u->buflen + min_bs - 1) / min_bs;
blocks = 0;
busy_check = !(io_u->flags & IO_U_F_BUSY_OK);
while (nr_blocks) {
unsigned int idx, bit;
unsigned long mask, this_blocks;
/*
* If we have a mixed random workload, we may
* encounter blocks we already did IO to.
*/
if (!busy_check) {
blocks = nr_blocks;
break;
}
if ((td->o.ddir_seq_nr == 1) && !random_map_free(f, block))
break;
idx = RAND_MAP_IDX(f, block);
bit = RAND_MAP_BIT(f, block);
fio_assert(td, idx < f->num_maps);
this_blocks = nr_blocks;
if (this_blocks + bit > BLOCKS_PER_MAP)
this_blocks = BLOCKS_PER_MAP - bit;
do {
if (this_blocks == BLOCKS_PER_MAP)
mask = -1UL;
else
mask = ((1UL << this_blocks) - 1) << bit;
if (!(f->file_map[idx] & mask))
break;
this_blocks--;
} while (this_blocks);
if (!this_blocks)
break;
f->file_map[idx] |= mask;
nr_blocks -= this_blocks;
blocks += this_blocks;
block += this_blocks;
}
if ((blocks * min_bs) < io_u->buflen)
io_u->buflen = blocks * min_bs;
}
