On Mon, Jun 25, 2018 at 8:59 AM Flavio Leitner <fbl@xxxxxxxxxx> wrote: > XPS breaks because the queue mapping stored in the socket is not > available, so another random queue might be selected when the stack > needs to transmit something like a TCP ACK, or TCP Retransmissions. > That causes packet re-ordering and/or performance issues. Now let me look at the XPS part, a key question first: By queue mapping stored in socket, you mean sk_tx_queue_get(), which is only called in __netdev_pick_tx(), and of course even before hitting qdisc layer. However, veth device orphans the skb inside its veth_xmit(), (dev_forward_skb()), which is after going through qdisc layer. So, how could the skb_orphan() called _after_ XPS break XPS? We are talking about a simple netns-to-netns case, so XPS won't be hit again once leaves it. Another _dumb_ question: veth is virtual device, it has literally no queues, I know technically there is a queue for installing qdisc. So, why does even queue mapping matters here??? -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
