From: David Ahern <d...@cumulusnetworks.com> Date: Tue, 1 Dec 2015 21:42:45 -0800
> On 12/1/15 6:58 PM, Andi Kleen wrote: >>>> - skb_iff is either skb->dev->iff or 0. so it could be replaced with a >>>> single bit flag for the 0 case. >>> >>> ... and that one wouldn't work on ingress. >> >> Please explain. > > skb->dev is dropped fairly early in the Rx path. skb_iif is needed for > example for IP_CMSG_PKTINFO. Right, we cannot let skb->dev escape the software interrupt handler, yet we need some cheap reference to it for socket options et al. Andi, this is not a 15-20 minute problem to solve. Many very smart people have spent days/weeks/months trying to even discover reasonable ways in which to shrink sk_buff. The low hanging fruit has been gone for a very long time now. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
