Re: [PATCH net-next v4] net: mana: Use page pool fragments for RX buffers instead of full pages to improve memory efficiency.

[Jakub Kicinski]

On Mon, 11 Aug 2025 15:29:19 -0700 Dipayaan Roy wrote:
> -     if (apc->port_is_up)
> +     if (apc->port_is_up) {
> +             /* Re-create rxq's after xdp prog was loaded or unloaded.
> +              * Ex: re create rxq's to switch from full pages to smaller
> +              * size page fragments when xdp prog is unloaded and
> +              * vice-versa.
> +              */
> +
> +             /* Pre-allocate buffers to prevent failure in mana_attach */
> +             err = mana_pre_alloc_rxbufs(apc, ndev->mtu, apc->num_queues);
> +             if (err) {
> +                     NL_SET_ERR_MSG_MOD
> +                         (extack,
> +                         "XDP: Insufficient memory for tx/rx re-config");

This weird line breaking is not necessary, checkpatch understands that
string can go over line limit:

                        NL_SET_ERR_MSG_MOD(extack,
                                           "XDP: Insufficient memory for tx/rx 
re-config");

> +                     return err;

I think you already replaced the bpf program at this point? 
So the allocation should happen earlier. On failure changes
to the driver state should be undone.
-- 
pw-bot: cr