We don't stop rx polling socket during rx processing, this will lead unnecessary wakeups from under layer net devices (E.g sock_def_readable() form tun). Rx will be slowed down in this way. This patch avoids this by stop polling socket during rx processing. A small drawback is that this introduces some overheads in light load case because of the extra start/stop polling, but single netperf TCP_RR does not notice any change. In a super heavy load case, e.g using pktgen to inject packet to guest, we get about ~8.8% improvement on pps:
before: ~1240000 pkt/s after: ~1350000 pkt/s Signed-off-by: Jason Wang <jasow...@redhat.com> --- drivers/vhost/net.c | 56 +++++++++++++++++++++++++++-------------------------- 1 file changed, 29 insertions(+), 27 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 10ff494..e91603b 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -301,6 +301,32 @@ static bool vhost_can_busy_poll(struct vhost_dev *dev, !vhost_has_work(dev); } +static void vhost_net_disable_vq(struct vhost_net *n, + struct vhost_virtqueue *vq) +{ + struct vhost_net_virtqueue *nvq = + container_of(vq, struct vhost_net_virtqueue, vq); + struct vhost_poll *poll = n->poll + (nvq - n->vqs); + if (!vq->private_data) + return; + vhost_poll_stop(poll); +} + +static int vhost_net_enable_vq(struct vhost_net *n, + struct vhost_virtqueue *vq) +{ + struct vhost_net_virtqueue *nvq = + container_of(vq, struct vhost_net_virtqueue, vq); + struct vhost_poll *poll = n->poll + (nvq - n->vqs); + struct socket *sock; + + sock = vq->private_data; + if (!sock) + return 0; + + return vhost_poll_start(poll, sock->file); +} + static int vhost_net_tx_get_vq_desc(struct vhost_net *net, struct vhost_virtqueue *vq, struct iovec iov[], unsigned int iov_size, @@ -627,6 +653,7 @@ static void handle_rx(struct vhost_net *net) if (!sock) goto out; vhost_disable_notify(&net->dev, vq); + vhost_net_disable_vq(net, vq); vhost_hlen = nvq->vhost_hlen; sock_hlen = nvq->sock_hlen; @@ -715,9 +742,10 @@ static void handle_rx(struct vhost_net *net) total_len += vhost_len; if (unlikely(total_len >= VHOST_NET_WEIGHT)) { vhost_poll_queue(&vq->poll); - break; + goto out; } } + vhost_net_enable_vq(net, vq); out: mutex_unlock(&vq->mutex); } @@ -796,32 +824,6 @@ static int vhost_net_open(struct inode *inode, struct file *f) return 0; } -static void vhost_net_disable_vq(struct vhost_net *n, - struct vhost_virtqueue *vq) -{ - struct vhost_net_virtqueue *nvq = - container_of(vq, struct vhost_net_virtqueue, vq); - struct vhost_poll *poll = n->poll + (nvq - n->vqs); - if (!vq->private_data) - return; - vhost_poll_stop(poll); -} - -static int vhost_net_enable_vq(struct vhost_net *n, - struct vhost_virtqueue *vq) -{ - struct vhost_net_virtqueue *nvq = - container_of(vq, struct vhost_net_virtqueue, vq); - struct vhost_poll *poll = n->poll + (nvq - n->vqs); - struct socket *sock; - - sock = vq->private_data; - if (!sock) - return 0; - - return vhost_poll_start(poll, sock->file); -} - static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct vhost_virtqueue *vq) { -- 1.8.3.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization