Jason Wang
2021-Apr-14 03:32 UTC
[PATCH net-next v4 06/10] virtio-net: unify the code for recycling the xmit ptr
? 2021/4/13 ??11:15, Xuan Zhuo ??:> Now there are two types of "skb" and "xdp frame" during recycling old > xmit. > > There are two completely similar and independent implementations. This > is inconvenient for the subsequent addition of new types. So extract a > function from this piece of code and call this function uniformly to > recover old xmit ptr. > > Rename free_old_xmit_skbs() to free_old_xmit(). > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > --- > drivers/net/virtio_net.c | 86 ++++++++++++++++++---------------------- > 1 file changed, 38 insertions(+), 48 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 52653e234a20..f3752b254965 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -264,6 +264,30 @@ static struct xdp_frame *ptr_to_xdp(void *ptr) > return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG); > } > > +static void __free_old_xmit(struct send_queue *sq, bool in_napi, > + struct virtnet_sq_stats *stats) > +{ > + unsigned int len; > + void *ptr; > + > + while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) { > + if (likely(!is_xdp_frame(ptr))) {So I think we need to drop likely here because it could be called by skb path. Other looks good. Thanks> + struct sk_buff *skb = ptr; > + > + pr_debug("Sent skb %p\n", skb); > + > + stats->bytes += skb->len; > + napi_consume_skb(skb, in_napi); > + } else { > + struct xdp_frame *frame = ptr_to_xdp(ptr); > + > + stats->bytes += frame->len; > + xdp_return_frame(frame); > + } > + stats->packets++; > + } > +} > + > /* Converting between virtqueue no. and kernel tx/rx queue no. > * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq > */ > @@ -525,15 +549,12 @@ static int virtnet_xdp_xmit(struct net_device *dev, > int n, struct xdp_frame **frames, u32 flags) > { > struct virtnet_info *vi = netdev_priv(dev); > + struct virtnet_sq_stats stats = {}; > struct receive_queue *rq = vi->rq; > struct bpf_prog *xdp_prog; > struct send_queue *sq; > - unsigned int len; > - int packets = 0; > - int bytes = 0; > int nxmit = 0; > int kicks = 0; > - void *ptr; > int ret; > int i; > > @@ -552,20 +573,7 @@ static int virtnet_xdp_xmit(struct net_device *dev, > } > > /* Free up any pending old buffers before queueing new ones. */ > - while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) { > - if (likely(is_xdp_frame(ptr))) { > - struct xdp_frame *frame = ptr_to_xdp(ptr); > - > - bytes += frame->len; > - xdp_return_frame(frame); > - } else { > - struct sk_buff *skb = ptr; > - > - bytes += skb->len; > - napi_consume_skb(skb, false); > - } > - packets++; > - } > + __free_old_xmit(sq, false, &stats); > > for (i = 0; i < n; i++) { > struct xdp_frame *xdpf = frames[i]; > @@ -582,8 +590,8 @@ static int virtnet_xdp_xmit(struct net_device *dev, > } > out: > u64_stats_update_begin(&sq->stats.syncp); > - sq->stats.bytes += bytes; > - sq->stats.packets += packets; > + sq->stats.bytes += stats.bytes; > + sq->stats.packets += stats.packets; > sq->stats.xdp_tx += n; > sq->stats.xdp_tx_drops += n - nxmit; > sq->stats.kicks += kicks; > @@ -1406,39 +1414,21 @@ static int virtnet_receive(struct receive_queue *rq, int budget, > return stats.packets; > } > > -static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi) > +static void free_old_xmit(struct send_queue *sq, bool in_napi) > { > - unsigned int len; > - unsigned int packets = 0; > - unsigned int bytes = 0; > - void *ptr; > - > - while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) { > - if (likely(!is_xdp_frame(ptr))) { > - struct sk_buff *skb = ptr; > - > - pr_debug("Sent skb %p\n", skb); > + struct virtnet_sq_stats stats = {}; > > - bytes += skb->len; > - napi_consume_skb(skb, in_napi); > - } else { > - struct xdp_frame *frame = ptr_to_xdp(ptr); > - > - bytes += frame->len; > - xdp_return_frame(frame); > - } > - packets++; > - } > + __free_old_xmit(sq, in_napi, &stats); > > /* Avoid overhead when no packets have been processed > * happens when called speculatively from start_xmit. > */ > - if (!packets) > + if (!stats.packets) > return; > > u64_stats_update_begin(&sq->stats.syncp); > - sq->stats.bytes += bytes; > - sq->stats.packets += packets; > + sq->stats.bytes += stats.bytes; > + sq->stats.packets += stats.packets; > u64_stats_update_end(&sq->stats.syncp); > } > > @@ -1463,7 +1453,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq) > return; > > if (__netif_tx_trylock(txq)) { > - free_old_xmit_skbs(sq, true); > + free_old_xmit(sq, true); > __netif_tx_unlock(txq); > } > > @@ -1548,7 +1538,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) > > txq = netdev_get_tx_queue(vi->dev, index); > __netif_tx_lock(txq, raw_smp_processor_id()); > - free_old_xmit_skbs(sq, true); > + free_old_xmit(sq, true); > __netif_tx_unlock(txq); > > virtqueue_napi_complete(napi, sq->vq, 0); > @@ -1617,7 +1607,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > bool use_napi = sq->napi.weight; > > /* Free up any pending old buffers before queueing new ones. */ > - free_old_xmit_skbs(sq, false); > + free_old_xmit(sq, false); > > if (use_napi && kick) > virtqueue_enable_cb_delayed(sq->vq); > @@ -1661,7 +1651,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > if (!use_napi && > unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > /* More just got used, free them then recheck. */ > - free_old_xmit_skbs(sq, false); > + free_old_xmit(sq, false); > if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { > netif_start_subqueue(dev, qnum); > virtqueue_disable_cb(sq->vq);