Function vm_pqbatch_process_page

freebsd/vm/vm_page.c:3530–3570

* Apply deferred queue state updates to a page. */

 * Apply deferred queue state updates to a page.
 */
static inline void
vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m, uint8_t queue)
{
	vm_page_astate_t new, old;

	CRITICAL_ASSERT(curthread);
	vm_pagequeue_assert_locked(pq);
	KASSERT(queue < PQ_COUNT,
	    ("%s: invalid queue index %d", __func__, queue));
	KASSERT(pq == _vm_page_pagequeue(m, queue),
	    ("%s: page %p does not belong to queue %p", __func__, m, pq));

	for (old = vm_page_astate_load(m);;) {
		if (__predict_false(old.queue != queue ||
		    (old.flags & PGA_QUEUE_OP_MASK) == 0)) {
			counter_u64_add(queue_nops, 1);
			break;
		}
		KASSERT(old.queue != PQ_NONE ||
		    (old.flags & PGA_QUEUE_STATE_MASK) == 0,
		    ("%s: page %p has unexpected queue state", __func__, m));

		new = old;
		if ((old.flags & PGA_DEQUEUE) != 0) {
			new.flags &= ~PGA_QUEUE_OP_MASK;
			new.queue = PQ_NONE;
			if (__predict_true(_vm_page_pqstate_commit_dequeue(pq,
			    m, &old, new))) {
				counter_u64_add(queue_ops, 1);
				break;
			}
		} else {
			new.flags &= ~(PGA_REQUEUE | PGA_REQUEUE_HEAD);
			if (__predict_true(_vm_page_pqstate_commit_requeue(pq,
			    m, &old, new))) {
				counter_u64_add(queue_ops, 1);
				break;
			}
		}
	}
}

static void
vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq,