On Thu, Sep 30, 2021 at 10:19:20AM -0700, Jakub Kicinski wrote: > On Thu, 30 Sep 2021 19:12:53 +0200 Lukas Wunner wrote: > > On Thu, Sep 30, 2021 at 07:28:35AM -0700, Jakub Kicinski wrote: > > > On Thu, 30 Sep 2021 11:21:42 +0200 Pablo Neira Ayuso wrote: > > > > this is stuffing one more bit into the skbuff > > > > > > The lifetime of this information is constrained, can't it be a percpu > > > flag, like xmit_more? > > > > Hm, can't an skb be queued and processed later on a different cpu? > > E.g. what about fragments? > > > > That would rule out a percpu flag, leaving a flag in struct sk_buff > > as the only option. > > What queuing do you have in mind? Qdisc is after the egress hook. Ingress queueing. E.g. a packet may be redirected or mirrored by tc on ingress to another interface, resulting in a recursive call to netif_receive_skb() or dev_queue_xmit(). The packet may be bounced around an arbitrary number of times this way. Forwarding like that can happen both at the tc and the netfilter "layer". I'm concerned that a packet may be handled by different cpus along the way and queueing might be one possibility how this could happen. Thanks, Lukas
