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

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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: Jason Wang <jasowang@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2014-01-16 14:45:24 +08:00 committed by David S. Miller
parent 9b05f462b7
commit be121f46af
1 changed files with 3 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
drivers/net/virtio_net.c
View file

@ -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 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
}
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 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
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;