On Tue, 2013-05-21 at 01:28 +0100, Ben Hutchings wrote: > I'm seeing packet loss when forwarding from a LAN to PPP, whenever GRO > kicks in on the LAN interface. > > On Mon, 2013-05-20 at 05:48 +0100, Ben Hutchings wrote: > [...] > > The Windows system is connected to the LAN interface (int0). Turning > > off GRO on this interface works around the problem. But since GRO is > > on by default, it clearly ought to work properly with iptables. > > > > I'll try to work out where the drops are occurring, but the > > perf net_dropmonitor script is also broken... > [...] > > I've fixed that script and now I can see that it's not iptables but > tbf_enqueue() that is dropping the GRO'd packets. I do traffic-shaping > on the PPP link like this: > > tc qdisc replace dev ppp0 root tbf rate 420kbit latency 50ms burst 1540 > > The local TCP will never generate an skb larger than the burst size > because it knows the PPP interface can't do GSO or TSO. And the wifi > network doesn't seem to be fast enough for GRO to have much of an > effect. But a peer on the wired network can trigger GRO and this > produces an skb that exceeds the burst size. > > Is this a bug in sch_tbf, or should I accept it as a limitation? It > seems like it should do GSO on entry to the queue if necessary. >
This has been discussed on netdev this year. Jiri Pirko was working on this. (thread : tbf: take into account gso skbs) -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1369097605.3301.203.camel@edumazet-glaptop
