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 <ru...@rustcorp.com.au>
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
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 c51a988..4e1bce3 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;
--
1.8.3.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
