diff options
| author | Jason Wang <jasowang@redhat.com> | 2016-06-30 14:45:36 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-07-01 05:32:17 -0400 |
| commit | 1576d98605998fb59d121a39581129e134217182 (patch) | |
| tree | 20949c1b4243a0e746570b3f08483b40c183ae57 /drivers/vhost | |
| parent | 08294a26e15d7baf1e14ee569e9f2bc82a7ae768 (diff) | |
| download | linux-1576d98605998fb59d121a39581129e134217182.tar.bz2 | |
tun: switch to use skb array for tx
We used to queue tx packets in sk_receive_queue, this is less
efficient since it requires spinlocks to synchronize between producer
and consumer.
This patch tries to address this by:
- switch from sk_receive_queue to a skb_array, and resize it when
tx_queue_len was changed.
- introduce a new proto_ops peek_len which was used for peeking the
skb length.
- implement a tun version of peek_len for vhost_net to use and convert
vhost_net to use peek_len if possible.
Pktgen test shows about 15.3% improvement on guest receiving pps for small
buffers:
Before: ~1300000pps
After : ~1500000pps
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/net.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 1d3e45f84549..e032ca397371 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -481,10 +481,14 @@ out: static int peek_head_len(struct sock *sk) { + struct socket *sock = sk->sk_socket; struct sk_buff *head; int len = 0; unsigned long flags; + if (sock->ops->peek_len) + return sock->ops->peek_len(sock); + spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); head = skb_peek(&sk->sk_receive_queue); if (likely(head)) { @@ -497,6 +501,16 @@ static int peek_head_len(struct sock *sk) return len; } +static int sk_has_rx_data(struct sock *sk) +{ + struct socket *sock = sk->sk_socket; + + if (sock->ops->peek_len) + return sock->ops->peek_len(sock); + + return skb_queue_empty(&sk->sk_receive_queue); +} + static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) { struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; @@ -513,7 +527,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) endtime = busy_clock() + vq->busyloop_timeout; while (vhost_can_busy_poll(&net->dev, endtime) && - skb_queue_empty(&sk->sk_receive_queue) && + !sk_has_rx_data(sk) && vhost_vq_avail_empty(&net->dev, vq)) cpu_relax_lowlatency(); |