On 2018年08月19日 20:11, xiangxia.m....@gmail.com wrote:
From: Tonghao Zhang <xiangxia.m....@gmail.com> Factor out generic busy polling logic and will be used for in tx path in the next patch. And with the patch, qemu can set differently the busyloop_timeout for rx queue. To avoid duplicate codes, introduce the helper functions: * sock_has_rx_data(changed from sk_has_rx_data) * vhost_net_busy_poll_try_queue Signed-off-by: Tonghao Zhang <xiangxia.m....@gmail.com> --- drivers/vhost/net.c | 111 +++++++++++++++++++++++++++++++++------------------- 1 file changed, 71 insertions(+), 40 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 32c1b52..453c061 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -440,6 +440,75 @@ static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq) nvq->done_idx = 0; }+static int sock_has_rx_data(struct socket *sock)+{ + if (unlikely(!sock)) + return 0; + + if (sock->ops->peek_len) + return sock->ops->peek_len(sock); + + return skb_queue_empty(&sock->sk->sk_receive_queue); +} + +static void vhost_net_busy_poll_try_queue(struct vhost_net *net, + struct vhost_virtqueue *vq) +{ + if (!vhost_vq_avail_empty(&net->dev, vq)) { + vhost_poll_queue(&vq->poll); + } else if (unlikely(vhost_enable_notify(&net->dev, vq))) { + vhost_disable_notify(&net->dev, vq); + vhost_poll_queue(&vq->poll); + } +} + +static void vhost_net_busy_poll(struct vhost_net *net, + struct vhost_virtqueue *rvq, + struct vhost_virtqueue *tvq, + bool *busyloop_intr, + bool poll_rx) +{ + unsigned long busyloop_timeout; + unsigned long endtime; + struct socket *sock; + struct vhost_virtqueue *vq = poll_rx ? tvq : rvq; + + mutex_lock_nested(&vq->mutex, poll_rx ? VHOST_NET_VQ_TX: VHOST_NET_VQ_RX); + vhost_disable_notify(&net->dev, vq); + sock = rvq->private_data; + + busyloop_timeout = poll_rx ? rvq->busyloop_timeout: + tvq->busyloop_timeout; + + preempt_disable(); + endtime = busy_clock() + busyloop_timeout; + + while (vhost_can_busy_poll(endtime)) { + if (vhost_has_work(&net->dev)) { + *busyloop_intr = true; + break; + } + + if ((sock_has_rx_data(sock) && + !vhost_vq_avail_empty(&net->dev, rvq)) || + !vhost_vq_avail_empty(&net->dev, tvq)) + break; + + cpu_relax(); + } + + preempt_enable(); + + if (poll_rx) + vhost_net_busy_poll_try_queue(net, tvq); + else if (sock_has_rx_data(sock)) + vhost_net_busy_poll_try_queue(net, rvq);
This could be simplified like: if (poll_rx || sock_has_rx_data(sock)) vhost_net_busy_poll_try_queue(net, vq); Thanks
+ else /* On tx here, sock has no rx data. */ + vhost_enable_notify(&net->dev, rvq); + + mutex_unlock(&vq->mutex); +} + static int vhost_net_tx_get_vq_desc(struct vhost_net *net, struct vhost_net_virtqueue *nvq, unsigned int *out_num, unsigned int *in_num, @@ -753,16 +822,6 @@ static int peek_head_len(struct vhost_net_virtqueue *rvq, 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, bool *busyloop_intr) { @@ -770,41 +829,13 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk, struct vhost_net_virtqueue *tnvq = &net->vqs[VHOST_NET_VQ_TX]; struct vhost_virtqueue *rvq = &rnvq->vq; struct vhost_virtqueue *tvq = &tnvq->vq; - unsigned long uninitialized_var(endtime); int len = peek_head_len(rnvq, sk);- if (!len && tvq->busyloop_timeout) {+ if (!len && rvq->busyloop_timeout) { /* Flush batched heads first */ vhost_net_signal_used(rnvq); /* Both tx vq and rx socket were polled here */ - mutex_lock_nested(&tvq->mutex, VHOST_NET_VQ_TX); - vhost_disable_notify(&net->dev, tvq); - - preempt_disable(); - endtime = busy_clock() + tvq->busyloop_timeout; - - while (vhost_can_busy_poll(endtime)) { - if (vhost_has_work(&net->dev)) { - *busyloop_intr = true; - break; - } - if ((sk_has_rx_data(sk) && - !vhost_vq_avail_empty(&net->dev, rvq)) || - !vhost_vq_avail_empty(&net->dev, tvq)) - break; - cpu_relax(); - } - - preempt_enable(); - - if (!vhost_vq_avail_empty(&net->dev, tvq)) { - vhost_poll_queue(&tvq->poll); - } else if (unlikely(vhost_enable_notify(&net->dev, tvq))) { - vhost_disable_notify(&net->dev, tvq); - vhost_poll_queue(&tvq->poll); - } - - mutex_unlock(&tvq->mutex); + vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, true);len = peek_head_len(rnvq, sk);}
_______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
