On Mon, 29 Jul 2024 20:47:55 +0800 Heng Qi wrote:
> Subject: [PATCH net] virtio_net: Avoid sending unnecessary vq coalescing commands
subject currently reads like this is an optimization, could you
rephrase?
> From the virtio spec:
>
> The driver MUST have negotiated the VIRTIO_NET_F_VQ_NOTF_COAL
> feature when issuing commands VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET
> and VIRTIO_NET_CTRL_NOTF_COAL_VQ_GET.
>
> The driver must not send vq notification coalescing commands if
> VIRTIO_NET_F_VQ_NOTF_COAL is not negotiated. This limitation of course
> applies to vq resize.
>
> Fixes: f61fe5f081cf ("virtio-net: fix the vq coalescing setting for vq resize")
> Signed-off-by: Heng Qi <hengqi@xxxxxxxxxxxxxxxxx>
> ---
> drivers/net/virtio_net.c | 29 +++++++++++++++++------------
> 1 file changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 0383a3e136d6..eb115e807882 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -3708,6 +3708,7 @@ static int virtnet_set_ringparam(struct net_device *dev,
> u32 rx_pending, tx_pending;
> struct receive_queue *rq;
> struct send_queue *sq;
> + u32 pkts, usecs;
> int i, err;
>
> if (ring->rx_mini_pending || ring->rx_jumbo_pending)
> @@ -3740,11 +3741,13 @@ static int virtnet_set_ringparam(struct net_device *dev,
> * through the VIRTIO_NET_CTRL_NOTF_COAL_TX_SET command, or, if the driver
> * did not set any TX coalescing parameters, to 0.
> */
> - err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i,
> - vi->intr_coal_tx.max_usecs,
> - vi->intr_coal_tx.max_packets);
> - if (err)
> - return err;
> + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
> + usecs = vi->intr_coal_tx.max_usecs;
> + pkts = vi->intr_coal_tx.max_packets;
> + err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i, usecs, pkts);
> + if (err)
> + return err;
Can you check the feature inside the
virtnet_send_.x_ctrl_coal_vq_cmd() helpers?
5 levels of indentation is a bit much
--
pw-bot: cr
