Re: [net-next PATCH v2 3/5] virtio_net: remove duplicate queue pair binding in XDP

[Jason Wang]

On 2017年02月03日 11:15, John Fastabend wrote:

Factor out qp assignment.

Signed-off-by: John Fastabend <john.r.fastab...@intel.com>

Acked-by: Jason Wang <jasow...@redhat.com>

---
  drivers/net/virtio_net.c |   20 +++++++-------------
  1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3b49363..dba5afb 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -341,15 +341,19 @@ static struct sk_buff *page_to_skb(struct virtnet_info 
*vi,

static bool virtnet_xdp_xmit(struct virtnet_info *vi,

                             struct receive_queue *rq,
-                            struct send_queue *sq,
                             struct xdp_buff *xdp,
                             void *data)
  {
        struct virtio_net_hdr_mrg_rxbuf *hdr;
        unsigned int num_sg, len;
+       struct send_queue *sq;
+       unsigned int qp;
        void *xdp_sent;
        int err;

+ qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id();

+       sq = &vi->sq[qp];
+
        /* Free up any pending old buffers before queueing new ones. */
        while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
                if (vi->mergeable_rx_bufs) {
@@ -415,7 +419,6 @@ static struct sk_buff *receive_small(struct net_device *dev,
        if (xdp_prog) {
                struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
                struct xdp_buff xdp;
-               unsigned int qp;
                u32 act;

if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))

@@ -429,11 +432,7 @@ static struct sk_buff *receive_small(struct net_device 
*dev,
                case XDP_PASS:
                        break;
                case XDP_TX:
-                       qp = vi->curr_queue_pairs -
-                               vi->xdp_queue_pairs +
-                               smp_processor_id();
-                       if (unlikely(!virtnet_xdp_xmit(vi, rq, &vi->sq[qp],
-                                                      &xdp, skb)))
+                       if (unlikely(!virtnet_xdp_xmit(vi, rq, &xdp, skb)))
                                trace_xdp_exception(vi->dev, xdp_prog, act);
                        rcu_read_unlock();
                        goto xdp_xmit;
@@ -560,7 +559,6 @@ static struct sk_buff *receive_mergeable(struct net_device 
*dev,
        if (xdp_prog) {
                struct page *xdp_page;
                struct xdp_buff xdp;
-               unsigned int qp;
                void *data;
                u32 act;

@@ -602,11 +600,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,

                        }
                        break;
                case XDP_TX:
-                       qp = vi->curr_queue_pairs -
-                               vi->xdp_queue_pairs +
-                               smp_processor_id();
-                       if (unlikely(!virtnet_xdp_xmit(vi, rq, &vi->sq[qp],
-                                                      &xdp, data)))
+                       if (unlikely(!virtnet_xdp_xmit(vi, rq, &xdp, data)))
                                trace_xdp_exception(vi->dev, xdp_prog, act);
                        ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);
                        if (unlikely(xdp_page != page))