On Fri, 13 Dec 2013 07:55:03 +0800 Li Zhong <zhong@xxxxxxxxxxxxxxxxxx> wrote: > On Wed, 2013-12-11 at 10:55 +0100, Daniel Borkmann wrote: > > On 12/12/2013 07:10 AM, Li Zhong wrote: [...] > > > Also, it seems that we could move skb_set_queue_mapping() into > > > packet_pick_tx_queue(), so we avoid calling it one more time > > > unnecessarily if we are going into the normal dev_queue_xmit() code > > > path. > > > > I don't agree with that part, I think this can be also beneficiary for > > packets without direct xmit, as in PF_PACKET we don't have a notion of > > "flow" but just raw packets instead, and can keep the mapping local > > depending on the current CPU as we do queue setting elsewhere in the > > stack just as well. > > It seems to me that the newly added xmit in packet_sock is > dev_queue_xmit() by default, and in this default case, dev_queue_xmit() > would call netdev_pick_tx(), which would set the skb queue_mapping again > to override the value based on the current CPU. Yes, I think you are right, that is also my experience with the code path. > Or did I miss something here? A bit related; One thing I'm missing to understand, is why the RAW/PF_PACKET sockets have a NULL in skb->sk when they reach __netdev_pick_tx() ? (resulting in they cannot store/cache the queue in sk_tx_queue_set) -- Best regards, Jesper Dangaard Brouer MSc.CS, Sr. Network Kernel Developer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
