Commit be121f46 authored by Jason Wang's avatar Jason Wang Committed by David S. Miller
Browse files

virtio-net: drop rq->max and rq->num 



It looks like there's no need for those two fields:

- Unless there's a failure for the first refill try, rq->max should be always
  equal to the vring size.
- rq->num is only used to determine the condition that we need to do the refill,
  we could check vq->num_free instead.
- rq->num was required to be increased or decreased explicitly after each
  get/put which results a bad API.

So this patch removes them both to make the code simpler.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9b05f462

drivers/net/virtio_net.c

+3 −13
Original line number Diff line number Diff line
@@ -72,9 +72,6 @@ struct receive_queue { 


	struct napi_struct napi;



	/* Number of input buffers, and max we've ever had. */

	unsigned int num, max;



	/* Chain pages by the private ptr. */

	struct page *pages;
@@ -360,7 +357,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, 
		}



		page = virt_to_head_page(buf);

		--rq->num;



		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;

		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {
@@ -406,7 +402,6 @@ err_skb: 
		}

		page = virt_to_head_page(buf);

		put_page(page);

		--rq->num;

	}

err_buf:

	dev->stats.rx_dropped++;
@@ -628,10 +623,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t gfp) 
		oom = err == -ENOMEM;

		if (err)

			break;

		++rq->num;

	} while (rq->vq->num_free);

	if (unlikely(rq->num > rq->max))

		rq->max = rq->num;

	if (unlikely(!virtqueue_kick(rq->vq)))

		return false;

	return !oom;
@@ -699,11 +691,10 @@ again: 
	while (received < budget &&

	       (buf = virtqueue_get_buf(rq->vq, &len)) != NULL) {

		receive_buf(rq, buf, len);

		--rq->num;

		received++;

	}



	if (rq->num < rq->max / 2) {

	if (rq->vq->num_free > virtqueue_get_vring_size(rq->vq) / 2) {

		if (!try_fill_recv(rq, GFP_ATOMIC))

			schedule_delayed_work(&vi->refill, 0);

	}
@@ -1398,9 +1389,7 @@ static void free_unused_bufs(struct virtnet_info *vi) 
				give_pages(&vi->rq[i], buf);

			else

				dev_kfree_skb(buf);

			--vi->rq[i].num;

		}

		BUG_ON(vi->rq[i].num != 0);

	}

}
@@ -1671,7 +1660,8 @@ static int virtnet_probe(struct virtio_device *vdev) 
		try_fill_recv(&vi->rq[i], GFP_KERNEL);



		/* If we didn't even get one input buffer, we're useless. */

		if (vi->rq[i].num == 0) {

		if (vi->rq[i].vq->num_free ==

		    virtqueue_get_vring_size(vi->rq[i].vq)) {

			free_unused_bufs(vi);

			err = -ENOMEM;

			goto free_recv_bufs;

CRA Git | Maintained and supported by SUSTech CRA and CCSE