On 9/4/20 9:59 AM, Jesper Dangaard Brouer wrote: >> dev_rx for example seems like it could just be the netdev >> index rather than a pointer or perhaps can be removed completely. I >> believe it is only used for 1 use case (redirects to CPUMAP); maybe that >> code can be refactored to handle the dev outside of xdp_frame. > > The dev_rx is needed when creating an SKB from a xdp_frame (basically > skb->dev = rx_dev). Yes, that is done in cpumap, but I want to > generalize this. The veth also creates SKBs from xdp_frame, but use > itself as skb->dev. > > And yes, we could save some space storing the index instead, and trade > space for cycles in a lookup.
I think this can be managed without adding a reference to the xdp_frame. I'll start a separate thread on that. >> >> As for frame_sz, why does it need to be larger than a u16? > > Because PAGE_SIZE can be 64KiB on some archs. > ok, is there any alignment requirement? can frame_sz be number of 32-bit words? I believe bit shifts are cheap.
