Thanks Sugesh, But would you please help me further with why dpdkbond affects bandwidth? With the bond the bandwidth is only around 30Mbps, configurations are shown in previous post.
> On 19 Oct 2016, at 3:46 PM, Chandran, Sugesh <sugesh.chand...@intel.com> > wrote: > > > > Regards > _Sugesh > > From: discuss [mailto:discuss-boun...@openvswitch.org] On Behalf Of Zhang > Qiang > Sent: Wednesday, October 19, 2016 7:55 AM > To: geza.ge...@gmail.com > Cc: discuss <discuss@openvswitch.org> > Subject: Re: [ovs-discuss] DPDK bandwidth issue > > Geza, > Thanks for your insight. > > - What is the packet size you see these bandwidth values? > A: I've tried various packet sizes with iperf, no significant differences. > > - What endpoints do you use for traffic generation? > A: The bandwidth in question was measured from host to host, no VMs involved. > > Your second question got me thinking, maybe it's normal for the host's > network performance to drop when DPDK is deployed, because DPDK runs in the > userspace which is a gain for userspace virtual machines but not for the host? > [Sugesh] Yes, The packet to the host network handled by ovs-vswitchd main > thread , not the PMD, which implies low performance when compared to the > ports managed by PMD > > What about the bond problem? I've tried active-backup and balance-slb modes, > and balance-tcp is not supported by the physical switch, none of them change > the situation. > > On 10/19/2016 06:04 AM, Geza Gemes <geza.ge...@gmail.com> wrote: > > On 10/19/2016 05:37 AM, Zhang Qiang wrote: > >> Hi all, > >> > >> I'm using ovs 2.5.90 built with dpdk 16.04-1 on CentOS > >> 7.2(3.10.0-327). Seems the network bandwidth drops severely with dpdk > >> enabled, especially with dpdkbond. > >> > >> With the following setup, the bandwidth is only around 30Mbits/s: > >> > ovs-vsctl show > >> 72b1bac3-0f7d-40c9-9b84-cabeff7f5521 > >> Bridge "ovsbr0" > >> Port dpdkbond > >> Interface "dpdk1" > >> type: dpdk > >> Interface "dpdk0" > >> type: dpdk > >> Port "ovsbr0" > >> tag: 112 > >> Interface "ovsbr0" > >> type: internal > >> ovs_version: "2.5.90" > >> > >> With the bond removed and by only using dpdk0, the bandwidth is around > >> 850Mbits/s, still much lower than the performance of bare ovs which > >> nearly reaches the hardware limit of 1000Mbps. > >> > >> There're lines in /var/log/openvswitch/ovs-vswtichd.log showing ovs > >> using 100% CPU: > >> 2016-10-19T11:21:19.304Z|00480|poll_loop|INFO|wakeup due to [POLLIN] > >> on fd 64 (character device /dev/net/tun) at lib/netdev-linux.c:1132 > >> (100% CPU usage) > >> > >> I understand that dpdk PMD threads use cores to poll, but is it normal > >> for the ovs-vswitchd process to use 100% of CPU? Is this relevant? > >> > >> I've also tried to pin PMD threads to different cores other than > >> ovs-vswtichd's to eliminate possible impacts, didn't help. > >> > >> What am I doing wrong? Thanks. > >> > >> > >> > >> _______________________________________________ > >> discuss mailing list > >> discuss@openvswitch.org > >> http://openvswitch.org/mailman/listinfo/discuss > > > >Hi, > > > >A number of questions: > > > >- What is the packet size you see these bandwidth values? > > > >- What endpoints do you use for traffic generation? In order to benefit > >from DPDK you have to have the ports of your VM set up as dpdkvhostuser > >ports (and have them backed by hugepages). Otherwise the traffic will > >undergo additional userspace<->kernel copying. > > > >Using 100% CPU for the poll mode threads is the expected behavior. Also > >in order to achieve best performance please make sure, that no other > >processes will be scheduled to the cores allocated for DPDK. > > > >Cheers, > > > >Geza
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