On Thu, 16 Jan 2025 05:52:59 +0000, Joe Damato <jdamato@xxxxxxxxxx> wrote:
> Use persistent NAPI config so that NAPI IDs are not renumbered as queue
> counts change.
>
> $ sudo ethtool -l ens4 | tail -5 | egrep -i '(current|combined)'
> Current hardware settings:
> Combined: 4
>
> $ ./tools/net/ynl/pyynl/cli.py \
> --spec Documentation/netlink/specs/netdev.yaml \
> --dump queue-get --json='{"ifindex": 2}'
> [{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
> {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
> {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
> {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
> {'id': 0, 'ifindex': 2, 'type': 'tx'},
> {'id': 1, 'ifindex': 2, 'type': 'tx'},
> {'id': 2, 'ifindex': 2, 'type': 'tx'},
> {'id': 3, 'ifindex': 2, 'type': 'tx'}]
>
> Now adjust the queue count, note that the NAPI IDs are not renumbered:
>
> $ sudo ethtool -L ens4 combined 1
> $ ./tools/net/ynl/pyynl/cli.py \
> --spec Documentation/netlink/specs/netdev.yaml \
> --dump queue-get --json='{"ifindex": 2}'
> [{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
> {'id': 0, 'ifindex': 2, 'type': 'tx'}]
>
> $ sudo ethtool -L ens4 combined 8
> $ ./tools/net/ynl/pyynl/cli.py \
> --spec Documentation/netlink/specs/netdev.yaml \
> --dump queue-get --json='{"ifindex": 2}'
> [{'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'rx'},
> {'id': 1, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
> {'id': 2, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
> {'id': 3, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
> {'id': 4, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'},
> {'id': 5, 'ifindex': 2, 'napi-id': 8198, 'type': 'rx'},
> {'id': 6, 'ifindex': 2, 'napi-id': 8199, 'type': 'rx'},
> {'id': 7, 'ifindex': 2, 'napi-id': 8200, 'type': 'rx'},
> [...]
>
> Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
Reviewed-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> v2:
> - New in this v2. Adds persistent NAPI config so that NAPI IDs are
> not renumbered and napi_config settings are persisted.
>
> drivers/net/virtio_net.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index c6fda756dd07..52094596e94b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -6420,8 +6420,9 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
> INIT_DELAYED_WORK(&vi->refill, refill_work);
> for (i = 0; i < vi->max_queue_pairs; i++) {
> vi->rq[i].pages = NULL;
> - netif_napi_add_weight(vi->dev, &vi->rq[i].napi, virtnet_poll,
> - napi_weight);
> + netif_napi_add_config(vi->dev, &vi->rq[i].napi, virtnet_poll,
> + i);
> + vi->rq[i].napi.weight = napi_weight;
> netif_napi_add_tx_weight(vi->dev, &vi->sq[i].napi,
> virtnet_poll_tx,
> napi_tx ? napi_weight : 0);
> --
> 2.25.1
>
