void init_swap(){
swap_blk = block_get_role(BLOCK_SWAP);
ASSERT(swap_blk!=NULL);
uint32_t sectors_num = block_size (swap_blk);
// each sector is 512K, one page has 8 sectors
uint32_t slots_num = sectors_num/8;
size_t bm_pages = DIV_ROUND_UP (bitmap_buf_size (slots_num), PGSIZE);
uint8_t* base = palloc_get_multiple (PAL_ZERO|PAL_ASSERT, bm_pages);
swap_table = bitmap_create_in_buf (slots_num, base, bm_pages * PGSIZE);
lock_init(&swap_lock);
}
/* Initializes pool P as starting at START and ending at END,
naming it NAME for debugging purposes. */
static void
init_pool (struct pool *p, void *base, size_t page_cnt, const char *name)
{
/* We'll put pool's used_map at its base.
Calculate the space needed for the bitmap
and subtract it from the pool's size. */
size_t bm_pages = DIV_ROUND_UP (bitmap_buf_size (page_cnt), PGSIZE);
if (bm_pages > page_cnt)
PANIC ("Not enough memory in %s for bitmap.", name);
page_cnt -= bm_pages;
printf ("%zu pages available in %s.\n", page_cnt, name);
/* Initialize the pool. */
lock_init (&p->lock);
p->used_map = bitmap_create_in_buf (page_cnt, base, bm_pages * PGSIZE);
p->base = base + bm_pages * PGSIZE;
}
