On Tue, 16 Jun 2026 19:59:12 +0800, Menglong Dong <[email protected]> wrote: > For now, XDP_RING_NEED_WAKEUP is not supported properly by the virtio-net > in the tx path for example: we set xsk_set_tx_need_wakeup() in > virtnet_xsk_xmit(), but we didn't call xsk_clear_tx_need_wakeup() > anywhere, which means the user will call send() for every packet. > > We call xsk_set_tx_need_wakeup() after virtnet_xsk_xmit_batch() if sq->vq > is empty, as we can't be wakeup by the skb_xmit_done() in this case. > Otherwise, we will clear the wakeup flag. > > Race condition is considered for tx path. > > Fixes: 89f86675cb03 ("virtio_net: xsk: tx: support xmit xsk buffer")
This is not a bug, so we do not need this. And you post this to net-next. > Signed-off-by: Menglong Dong <[email protected]> > --- > v3: > - remove the confusing comment > > v2: > - add the Fixes tag > --- > drivers/net/virtio_net.c | 23 +++++++++++++++++++---- > 1 file changed, 19 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index f4adcfee7a80..6e099edef6e9 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1440,8 +1440,9 @@ static bool virtnet_xsk_xmit(struct send_queue *sq, > struct xsk_buff_pool *pool, > struct virtnet_info *vi = sq->vq->vdev->priv; > struct virtnet_sq_free_stats stats = {}; > struct net_device *dev = vi->dev; > + int sent, vring_size; > + bool need_wakeup; > u64 kicks = 0; > - int sent; > > /* Avoid to wakeup napi meanless, so call __free_old_xmit instead of > * free_old_xmit(). > @@ -1451,8 +1452,25 @@ static bool virtnet_xsk_xmit(struct send_queue *sq, > struct xsk_buff_pool *pool, > if (stats.xsk) > xsk_tx_completed(sq->xsk_pool, stats.xsk); > > + vring_size = virtqueue_get_vring_size(sq->vq); > + need_wakeup = xsk_uses_need_wakeup(pool); > + > + if (need_wakeup && vring_size == sq->vq->num_free) > + xsk_set_tx_need_wakeup(pool); You need to comment this. > + > sent = virtnet_xsk_xmit_batch(sq, pool, budget, &kicks); > > + if (need_wakeup) { > + if (vring_size == sq->vq->num_free) > + /* we can't wake up by ourself, and it should be done > + * by the user. > + */ > + xsk_set_tx_need_wakeup(pool); > + else > + /* we can wake up from skb_xmit_done() */ > + xsk_clear_tx_need_wakeup(pool); > + } > + > if (!is_xdp_raw_buffer_queue(vi, sq - vi->sq)) > check_sq_full_and_disable(vi, vi->dev, sq); After fixed above comments, you can add: Reviewed-by: Xuan Zhuo <[email protected]> Thanks. > > @@ -1470,9 +1488,6 @@ static bool virtnet_xsk_xmit(struct send_queue *sq, > struct xsk_buff_pool *pool, > u64_stats_add(&sq->stats.xdp_tx, sent); > u64_stats_update_end(&sq->stats.syncp); > > - if (xsk_uses_need_wakeup(pool)) > - xsk_set_tx_need_wakeup(pool); > - > return sent; > } > > -- > 2.54.0 >
