B2ALLOC
p->total = p->free = MALLOC_PAGESIZE / B2ALLOC(bucket);
count = MALLOC_PAGESIZE / B2ALLOC(bucket);
B2ALLOC(bucket));
p = (char *)bp->page + k * B2ALLOC(bucket);
chunknum = ((uintptr_t)ptr & MALLOC_PAGEMASK) / B2ALLOC(info->bucket);