Re: [PATCH v2 2/3] virtio_net: Cleanup '2+MAX_SKB_FRAGS'

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

On Wed, 21 May 2025 11:22:35 +0200, Laurent Vivier <lvivier@redhat.com> wrote:
> Improve consistency by using everywhere it is needed
> 'MAX_SKB_FRAGS + 2' rather than '2+MAX_SKB_FRAGS' or
> '2 + MAX_SKB_FRAGS'.
>
> No functional change.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>

Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

> ---
>  drivers/net/virtio_net.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index e53ba600605a..ff4160243538 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1084,7 +1084,7 @@ static bool tx_may_stop(struct virtnet_info *vi,
>  	 * Since most packets only take 1 or 2 ring slots, stopping the queue
>  	 * early means 16 slots are typically wasted.
>  	 */
> -	if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
> +	if (sq->vq->num_free < MAX_SKB_FRAGS + 2) {
>  		struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum);
>
>  		netif_tx_stop_queue(txq);
> @@ -1116,7 +1116,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
>  		} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
>  			/* More just got used, free them then recheck. */
>  			free_old_xmit(sq, txq, false);
> -			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
> +			if (sq->vq->num_free >= MAX_SKB_FRAGS + 2) {
>  				netif_start_subqueue(dev, qnum);
>  				u64_stats_update_begin(&sq->stats.syncp);
>  				u64_stats_inc(&sq->stats.wake);
> @@ -2998,7 +2998,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq, int budget)
>  			free_old_xmit(sq, txq, !!budget);
>  		} while (unlikely(!virtqueue_enable_cb_delayed(sq->vq)));
>
> -		if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
> +		if (sq->vq->num_free >= MAX_SKB_FRAGS + 2) {
>  			if (netif_tx_queue_stopped(txq)) {
>  				u64_stats_update_begin(&sq->stats.syncp);
>  				u64_stats_inc(&sq->stats.wake);
> @@ -3195,7 +3195,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
>  	else
>  		free_old_xmit(sq, txq, !!budget);
>
> -	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) {
> +	if (sq->vq->num_free >= MAX_SKB_FRAGS + 2) {
>  		if (netif_tx_queue_stopped(txq)) {
>  			u64_stats_update_begin(&sq->stats.syncp);
>  			u64_stats_inc(&sq->stats.wake);
> --
> 2.49.0
>