Messages in this thread | | | Subject | Re: [PATCH net-next 8/8] vhost_net: use lockless peeking for skb array during busy polling | From | Jason Wang <> | Date | Thu, 30 Mar 2017 10:16:15 +0800 |
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On 2017年03月29日 20:07, Michael S. Tsirkin wrote: > On Tue, Mar 21, 2017 at 12:04:47PM +0800, Jason Wang wrote: >> For the socket that exports its skb array, we can use lockless polling >> to avoid touching spinlock during busy polling. >> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> drivers/vhost/net.c | 7 +++++-- >> 1 file changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c >> index 53f09f2..41153a3 100644 >> --- a/drivers/vhost/net.c >> +++ b/drivers/vhost/net.c >> @@ -551,10 +551,13 @@ static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk) >> return len; >> } >> >> -static int sk_has_rx_data(struct sock *sk) >> +static int sk_has_rx_data(struct vhost_net_virtqueue *rvq, struct sock *sk) >> { >> struct socket *sock = sk->sk_socket; >> >> + if (rvq->rx_array) >> + return !__skb_array_empty(rvq->rx_array); >> + >> if (sock->ops->peek_len) >> return sock->ops->peek_len(sock); >> > I don't see which patch adds __skb_array_empty.
This is not something new, it was introduced by ad69f35d1dc0a ("skb_array: array based FIFO for skbs").
Thanks
> >> @@ -579,7 +582,7 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, >> endtime = busy_clock() + vq->busyloop_timeout; >> >> while (vhost_can_busy_poll(&net->dev, endtime) && >> - !sk_has_rx_data(sk) && >> + !sk_has_rx_data(rvq, sk) && >> vhost_vq_avail_empty(&net->dev, vq)) >> cpu_relax(); >> >> -- >> 2.7.4
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