virtio: net refill on out-of-memory (3161e453) · Commits · 戴 / test

drivers/net/virtio_net.c

+46 −15

Original line number	Diff line number	Diff line
		@@ -70,6 +70,9 @@ struct virtnet_info
		struct sk_buff_head recv;
		struct sk_buff_head send;

		/* Work struct for refilling if we run low on memory. */
		struct delayed_work refill;

		/* Chain pages by the private ptr. */
		struct page *pages;
		};
		@@ -273,19 +276,22 @@ drop:
		dev_kfree_skb(skb);
		}

		static void try_fill_recv_maxbufs(struct virtnet_info *vi)
		static bool try_fill_recv_maxbufs(struct virtnet_info *vi, gfp_t gfp)
		{
		struct sk_buff *skb;
		struct scatterlist sg[2+MAX_SKB_FRAGS];
		int num, err, i;
		bool oom = false;

		sg_init_table(sg, 2+MAX_SKB_FRAGS);
		for (;;) {
		struct virtio_net_hdr *hdr;

		skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN);
		if (unlikely(!skb))
		if (unlikely(!skb)) {
		oom = true;
		break;
		}

		skb_reserve(skb, NET_IP_ALIGN);
		skb_put(skb, MAX_PACKET_LEN);
		@@ -296,7 +302,7 @@ static void try_fill_recv_maxbufs(struct virtnet_info *vi)
		if (vi->big_packets) {
		for (i = 0; i < MAX_SKB_FRAGS; i++) {
		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
		f->page = get_a_page(vi, GFP_ATOMIC);
		f->page = get_a_page(vi, gfp);
		if (!f->page)
		break;

		@@ -325,31 +331,35 @@ static void try_fill_recv_maxbufs(struct virtnet_info *vi)
		if (unlikely(vi->num > vi->max))
		vi->max = vi->num;
		vi->rvq->vq_ops->kick(vi->rvq);
		return !oom;
		}

		static void try_fill_recv(struct virtnet_info *vi)
		/* Returns false if we couldn't fill entirely (OOM). */
		static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
		{
		struct sk_buff *skb;
		struct scatterlist sg[1];
		int err;
		bool oom = false;

		if (!vi->mergeable_rx_bufs) {
		try_fill_recv_maxbufs(vi);
		return;
		}
		if (!vi->mergeable_rx_bufs)
		return try_fill_recv_maxbufs(vi, gfp);

		for (;;) {
		skb_frag_t *f;

		skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
		if (unlikely(!skb))
		if (unlikely(!skb)) {
		oom = true;
		break;
		}

		skb_reserve(skb, NET_IP_ALIGN);

		f = &skb_shinfo(skb)->frags[0];
		f->page = get_a_page(vi, GFP_ATOMIC);
		f->page = get_a_page(vi, gfp);
		if (!f->page) {
		oom = true;
		kfree_skb(skb);
		break;
		}
		@@ -373,6 +383,7 @@ static void try_fill_recv(struct virtnet_info *vi)
		if (unlikely(vi->num > vi->max))
		vi->max = vi->num;
		vi->rvq->vq_ops->kick(vi->rvq);
		return !oom;
		}

		static void skb_recv_done(struct virtqueue *rvq)
		@@ -385,6 +396,23 @@ static void skb_recv_done(struct virtqueue *rvq)
		}
		}

		static void refill_work(struct work_struct *work)
		{
		struct virtnet_info *vi;
		bool still_empty;

		vi = container_of(work, struct virtnet_info, refill.work);
		napi_disable(&vi->napi);
		try_fill_recv(vi, GFP_KERNEL);
		still_empty = (vi->num == 0);
		napi_enable(&vi->napi);

		/* In theory, this can happen: if we don't get any buffers in
		* we will never try to fill again. */
		if (still_empty)
		schedule_delayed_work(&vi->refill, HZ/2);
		}

		static int virtnet_poll(struct napi_struct *napi, int budget)
		{
		struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
		@@ -400,10 +428,10 @@ again:
		received++;
		}

		/* FIXME: If we oom and completely run out of inbufs, we need
		* to start a timer trying to fill more. */
		if (vi->num < vi->max / 2)
		try_fill_recv(vi);
		if (vi->num < vi->max / 2) {
		if (!try_fill_recv(vi, GFP_ATOMIC))
		schedule_delayed_work(&vi->refill, 0);
		}

		/* Out of packets? */
		if (received < budget) {
		@@ -893,6 +921,7 @@ static int virtnet_probe(struct virtio_device *vdev)
		vi->vdev = vdev;
		vdev->priv = vi;
		vi->pages = NULL;
		INIT_DELAYED_WORK(&vi->refill, refill_work);

		/* If they give us a callback when all buffers are done, we don't need
		* the timer. */
		@@ -941,7 +970,7 @@ static int virtnet_probe(struct virtio_device *vdev)
		}

		/* Last of all, set up some receive buffers. */
		try_fill_recv(vi);
		try_fill_recv(vi, GFP_KERNEL);

		/* If we didn't even get one input buffer, we're useless. */
		if (vi->num == 0) {
		@@ -958,6 +987,7 @@ static int virtnet_probe(struct virtio_device *vdev)

		unregister:
		unregister_netdev(dev);
		cancel_delayed_work_sync(&vi->refill);
		free_vqs:
		vdev->config->del_vqs(vdev);
		free:
		@@ -986,6 +1016,7 @@ static void virtnet_remove(struct virtio_device *vdev)
		BUG_ON(vi->num != 0);

		unregister_netdev(vi->dev);
		cancel_delayed_work_sync(&vi->refill);

		vdev->config->del_vqs(vi->vdev);

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