From be121f46affce8a2ba284ef0388a8ff6ff85ec1b Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 16 Jan 2014 14:45:24 +0800 Subject: [PATCH] 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 Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Acked-by: Rusty Russell Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7b172408cff0..9bd70aa87bf7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -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; -- 2.11.0