On 2023/4/24 21:10, Maciej Fijalkowski wrote: >>> There was a discussion in the past to reduce XDP_PACKET_HEADROOM to 192B but >>> this is not merged yet and it is not related to this series. We can address >>> your comments in a follow-up patch when XDP_PACKET_HEADROOM series is merged. > > Intel drivers still work just fine at 192 headroom and split the page but > it makes it problematic for BIG TCP where MAX_SKB_FRAGS from shinfo needs I am not sure why we are not enabling skb_shinfo(skb)->frag_list to support BIG TCP instead of increasing MAX_SKB_FRAGS, perhaps there was some disscution about this in the past I am not aware of? > to be increased. So it's the tailroom that becomes the bottleneck, not the > headroom. I believe at some point we will convert our drivers to page_pool > with full 4k page dedicated for a single frame. Can we use header splitting to ensure there is enough tailroom for napi_build_skb() or xdp_frame with shinfo?
