Re: [PATCH net-next v3 4/6] net: bcmgenet: add XDP_TX support

[Nicolai Buchwitz]

On 30.3.2026 20:15, Mohsin Bashir wrote:
> > +static bool
> > +bcmgenet_xdp_xmit_frame(struct bcmgenet_priv *priv,
> > +			struct xdp_frame *xdpf, bool dma_map)
> > +{
> > +	struct bcmgenet_tx_ring *ring = &priv->tx_rings[DESC_INDEX];
> > +	struct device *kdev = &priv->pdev->dev;
> > +	struct enet_cb *tx_cb_ptr;
> > +	dma_addr_t mapping;
> > +	unsigned int dma_len;
> > +	u32 len_stat;
> > +
> > +	spin_lock(&ring->lock);
> > +
>
> So we acquire lock on per-packet basis on the XDP_TX path? Do you think 
> we can batch this?

Patch 4 only has one caller so the lock inside was fine. Patch 5
adds ndo_xdp_xmit which needs batching, so it moves the lock out
to the callers. XDP_TX processes one frame at a time in NAPI context
so batching doesn't apply there.

Note: v5 of this series was posted two days ago [1].

[1] 
https://lore.kernel.org/netdev/20260328230513.415790-1-nb@xxxxxxxxxxx/

Thanks
Nicolai