Benjamin Thery wrote: > 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? Yup. You may try turn tso and sg on as well. > (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 >>> >> > > _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers