Commit 5db48105 authored by Xuan Zhuo's avatar Xuan Zhuo Committed by Jakub Kicinski
Browse files

virtio_net: separate receive_mergeable 



This commit separates the function receive_mergeable(),
put the logic of appending frag to the skb as an independent function.
The subsequent commit will reuse it.

Signed-off-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Link: https://patch.msgid.link/20240708112537.96291-6-xuanzhuo@linux.alibaba.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c86c120f

drivers/net/virtio_net.c

+47 −30
Original line number Diff line number Diff line
@@ -1821,6 +1821,49 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, 
	return NULL;

}



static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb,

					       struct sk_buff *curr_skb,

					       struct page *page, void *buf,

					       int len, int truesize)

{

	int num_skb_frags;

	int offset;



	num_skb_frags = skb_shinfo(curr_skb)->nr_frags;

	if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {

		struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);



		if (unlikely(!nskb))

			return NULL;



		if (curr_skb == head_skb)

			skb_shinfo(curr_skb)->frag_list = nskb;

		else

			curr_skb->next = nskb;

		curr_skb = nskb;

		head_skb->truesize += nskb->truesize;

		num_skb_frags = 0;

	}



	if (curr_skb != head_skb) {

		head_skb->data_len += len;

		head_skb->len += len;

		head_skb->truesize += truesize;

	}



	offset = buf - page_address(page);

	if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {

		put_page(page);

		skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,

				     len, truesize);

	} else {

		skb_add_rx_frag(curr_skb, num_skb_frags, page,

				offset, len, truesize);

	}



	return curr_skb;

}



static struct sk_buff *receive_mergeable(struct net_device *dev,

					 struct virtnet_info *vi,

					 struct receive_queue *rq,
@@ -1870,8 +1913,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, 
	if (unlikely(!curr_skb))

		goto err_skb;

	while (--num_buf) {

		int num_skb_frags;



		buf = virtnet_rq_get_buf(rq, &len, &ctx);

		if (unlikely(!buf)) {

			pr_debug("%s: rx error: %d buffers out of %d missing\n",
@@ -1896,34 +1937,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, 
			goto err_skb;

		}



		num_skb_frags = skb_shinfo(curr_skb)->nr_frags;

		if (unlikely(num_skb_frags == MAX_SKB_FRAGS)) {

			struct sk_buff *nskb = alloc_skb(0, GFP_ATOMIC);



			if (unlikely(!nskb))

		curr_skb  = virtnet_skb_append_frag(head_skb, curr_skb, page,

						    buf, len, truesize);

		if (!curr_skb)

			goto err_skb;

			if (curr_skb == head_skb)

				skb_shinfo(curr_skb)->frag_list = nskb;

			else

				curr_skb->next = nskb;

			curr_skb = nskb;

			head_skb->truesize += nskb->truesize;

			num_skb_frags = 0;

		}

		if (curr_skb != head_skb) {

			head_skb->data_len += len;

			head_skb->len += len;

			head_skb->truesize += truesize;

		}

		offset = buf - page_address(page);

		if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) {

			put_page(page);

			skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1,

					     len, truesize);

		} else {

			skb_add_rx_frag(curr_skb, num_skb_frags, page,

					offset, len, truesize);

		}

	}



	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);