* The memory overhead of the following tap table should be relatively small,
* no more than 400 bytes.
*/
-static uint8_t taps[64][FIO_MAX_TAPS] =
+static uint8_t lfsr_taps[64][FIO_MAX_TAPS] =
{
{0}, {0}, {0}, //LFSRs with less that 3-bits cannot exist
{3, 2}, //Tap position for 3-bit LFSR
* c. Check if the calculated value exceeds the desirable range. In this case,
* go back to b, else return.
*/
-int lfsr_next(struct fio_lfsr *fl, uint64_t *off, uint64_t last)
+int lfsr_next(struct fio_lfsr *fl, uint64_t *off)
{
if (fl->num_vals++ > fl->max_val)
return 1;
/*
* For an LFSR, there is always a prohibited state (all ones).
- * Thus, if we need to find the proper LFSR for our size, we must take that
- * into account.
+ * Thus, if we need to find the proper LFSR for our size, we must
+ * take that into account.
*/
for (i = 3; i < 64; i++)
if ((1UL << i) > size)
- return taps[i];
+ return lfsr_taps[i];
return NULL;
}
* Thus, [1] is equivalent to (y * i) % (spin + 1) == 0;
* Also, the cycle's length will be (x * i) + (y * i) / (spin + 1)
*/
-int prepare_spin(struct fio_lfsr *fl, unsigned int spin)
+static int prepare_spin(struct fio_lfsr *fl, unsigned int spin)
{
uint64_t max = (fl->cached_bit << 1) - 1;
uint64_t x, y;
int lfsr_init(struct fio_lfsr *fl, uint64_t nums, unsigned long seed,
unsigned int spin)
{
- uint8_t *lfsr_taps;
+ uint8_t *taps;
- lfsr_taps = find_lfsr(nums);
- if (!lfsr_taps)
+ taps = find_lfsr(nums);
+ if (!taps)
return 1;
fl->max_val = nums - 1;
- fl->xormask = lfsr_create_xormask(lfsr_taps);
- fl->cached_bit = 1UL << (lfsr_taps[0] - 1);
+ fl->xormask = lfsr_create_xormask(taps);
+ fl->cached_bit = 1UL << (taps[0] - 1);
if (prepare_spin(fl, spin))
return 1;