On Thu, 20 Apr 2017 18:50:21 -0700, Jeff Kirsher wrote:
> +static int ixgbe_xdp_queues(struct ixgbe_adapter *adapter)
> +{
> + if (nr_cpu_ids > MAX_XDP_QUEUES)
> + return 0;
> +
> + return adapter->xdp_prog ? nr_cpu_ids : 0;
> +}
Nit: AFAICT ixgbe_xdp_setup() will guarantee xdp_prog is not set if
there are too many CPU ids.
> @@ -6120,10 +6193,21 @@ static int ixgbe_setup_all_tx_resources(struct
> ixgbe_adapter *adapter)
> e_err(probe, "Allocation for Tx Queue %u failed\n", i);
> goto err_setup_tx;
> }
> + for (j = 0; j < adapter->num_xdp_queues; j++) {
> + err = ixgbe_setup_tx_resources(adapter->xdp_ring[j]);
> + if (!err)
> + continue;
> +
> + e_err(probe, "Allocation for Tx Queue %u failed\n", j);
> + goto err_setup_tx;
> + }
> +
>
Nit: extra line here
> @@ -9557,7 +9739,21 @@ static int ixgbe_xdp_setup(struct net_device *dev,
> struct bpf_prog *prog)
> return -EINVAL;
> }
>
> + if (nr_cpu_ids > MAX_XDP_QUEUES)
> + return -ENOMEM;
> +
> old_prog = xchg(&adapter->xdp_prog, prog);
> +
> + /* If transitioning XDP modes reconfigure rings */
> + if (!!prog != !!old_prog) {
> + int err = ixgbe_setup_tc(dev, netdev_get_num_tc(dev));
> +
> + if (err) {
> + rcu_assign_pointer(adapter->xdp_prog, old_prog);
> + return -EINVAL;
> + }
> + }
> +
> for (i = 0; i < adapter->num_rx_queues; i++)
> xchg(&adapter->rx_ring[i]->xdp_prog, adapter->xdp_prog);
>
In case of disabling XDP I assume ixgbe_setup_tc() will free the rings
before the xdp_prog on the rings is swapped to NULL. Is there anything
preventing TX in that time window? I think usual ordering would be to
install the prog after reconfig but uninstall before.
