On Thu, Mar 15, 2018 at 10:20 AM, Paolo Abeni <pab...@redhat.com> wrote: > Hi, > > On Thu, 2018-03-15 at 15:59 +0000, Eric Dumazet wrote: >> On Thu, Mar 15, 2018 at 8:51 AM Paolo Abeni <pab...@redhat.com> wrote: >> > I'm sorry, I do not follow. AFAICS with unconnected sockets without XPS >> > we always hit the netdev_pick_tx()/skb_tx_hash()/skb_flow_dissect() >> > overhead in xmit path. >> >> Then fix this if you want, instead of fixing one NIC only, or by enforcing >> XPS by all NIC. >> >> For unconnected sockets, picking the TX queue based on current cpu is good, >> we do not have to enforce ordering as much as possible. >> >> (pfifo_fast no longer can enforce it anyway) > > Thank you for the prompt reply. > > I'm double checking to avoid misinterpretation on my side: are you > suggesting to plug a CPU-based selection logic for unconnected sockets > in netdev_pick_tx() or to cook patches like 2/2 for all the relevant > NICs? > > Thanks! > > Paolo
We just need to watch out for any possible side effects. For example using XPS on a virtualization host has been problematic as you end up with the traffic getting reordered if the VM jumps from CPU to CPU. Thanks. - Alex
