Benjamin Thery wrote: > On Mon, Mar 3, 2008 at 3:55 PM, Pavel Emelyanov <xemul@xxxxxxxxxx> wrote: >> Benjamin Thery wrote: >> > Daniel Lezcano wrote: >> >> Hi, >> >> >> >> Some performance tests was made by Benjamin to watch out the impact of >> >> the network namespace. The good news is there is no impact when used >> >> with or without namespaces. That has been checked using a real network >> >> device inside a network namespace. >> >> >> >> These results are consistent with the ones previously made for ipv4. >> >> >> >> http://lxc.sourceforge.net/network/bench_ipv6_graph.php >> >> >> >> Thanks to Benjamin who did all the performance tests :) >> > >> > In these results, may be, there is one thing that should be explained. >> > It is the CPU utilization overhead in the 'veth' case. >> > >> > Compared to physical devices or macvlan, veth interfaces don't benefit >> > from hardware offloading mechanisms: i.e. checksums have to be computed >> > by the soft. That explains the big overhead in CPU utilization when >> >> You can tune the veth devices not to account checksum when unnecessary. > > Oh. This is interesting. > > You mean with ethtool -K rx/tx? > I will give it a try. Pavel, I had no luck with "ethtool -K veth0 rx on tx on". On my testbed, with these options TCP drops packets (trying to establish a ssh connection between init and child namespace). Then, I tested "ethtool -K veth0 rx on tx off". This time TCP (and netperf) work, but I see no difference in CPU load compared to the case without offloading. Can I tune veth differently? (BTW, I run netperf between a child namespace on host A and netserv on host B. The stream goes through the following interface: veth1 on A -> veth0 on A -> eth1 on A -> ("real network") -> eth1 on B) Benjamin > >> >> > using this kind of virtual interface. >> > >> > Benjamin >> > >> >> Regards >> >> -- Daniel >> >> > >> -- >> To unsubscribe from this list: send the line "unsubscribe netdev" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > -- B e n j a m i n T h e r y - BULL/DT/Open Software R&D http://www.bull.com _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers