> > Hi Ciara, > > These improvements look very good. I would expect even bigger > improvements for big packets, as long as we don't hit some link bandwidth > limitations. But at least the vhost-vhost cases should benefit. > > Have you also tested larger packet sizes?
Hi Jan, Thanks for the feedback. Here are some more datapoints for the VM2VM topology: 256B: 4.69 vs 5.42 Mpps (+~16%) 512B: 4.04 vs 4.90 Mpps (+~21%) 1518B: 2.51 vs 3.05 Mpps (+~22%) As you guessed, I hit bandwidth when using a NIC & larger packet sizes so can't show any benefit. > > I plan to review your patches. Much appreciated. Thanks, Ciara > > Thanks, Jan > > > -----Original Message----- > > From: [email protected] [mailto:ovs-dev- > [email protected]] On Behalf Of Ciara Loftus > > Sent: Wednesday, 11 October, 2017 16:22 > > To: [email protected] > > Subject: [ovs-dev] [PATCH v2 0/2] vHost Dequeue Zero Copy > > > > This patch enables optional dequeue zero copy for vHost ports. > > This gives a performance increase for some use cases. I'm using > > the cover letter to report my results. > > > > vhost (vm1) -> vhost (vm2) > > Using testpmd to source (txonly) in vm1 and sink (rxonly) in vm2. > > 4C1Q 64B packets: 5.05Mpps -> 5.52Mpps = 9.2% improvement > > > > vhost (virtio_user backend 1) -> vhost (virtio_user backend 2) > > Using 2 instances of testpmd, each with a virtio_user backend > > connected to one of the two vhost ports created in OVS. > > 2C1Q 1518B packets: 2.59Mpps -> 3.09Mpps = 19.3% improvement > > > > vhost -> phy > > Using testpmd to source (txonly) and sink in the NIC > > 1C1Q 64B packets: 6.81Mpps -> 7.76Mpps = 13.9% improvement > > > > phy -> vhost -> phy > > No improvement measured > > > > This patch is dependent on the series below which fixes issues with > > mempool management: > > https://patchwork.ozlabs.org/patch/822590/ > > > > v2 changes: > > * Mention feature is disabled by default in the documentation > > * Add PHY-VM-PHY with vHost dequeue zero copy documentation guide > > * Line wrap link to DPDK documentation > > * Rename zc_enabled to dq_zc_enabled for future-proofing > > * Mention feature is available for both vHost port types in the docs > > * In practise, rebooting the VM doesn't always enable the feature if > > enabled post-boot, so update the documentation to suggest a shutdown > > rather than a reboot. The reason why this doesn't work is probably > > because the total downtime during reboot isn't enough to allow a vhost > > device unregister & re-register with the new feature, so when the VM > > starts again it doesn't pick up the new device as it hasn't been > > re-registered in time. > > > > Ciara Loftus (2): > > netdev-dpdk: Helper function for vHost device setup > > netdev-dpdk: Enable optional dequeue zero copy for vHost User > > > > Documentation/howto/dpdk.rst | 29 +++++ > > Documentation/topics/dpdk/vhost-user.rst | 35 ++++++ > > NEWS | 3 + > > lib/netdev-dpdk.c | 202 > > +++++++++++++++++++++---------- > > vswitchd/vswitch.xml | 11 ++ > > 5 files changed, 218 insertions(+), 62 deletions(-) > > > > -- > > 2.7.5 > > > > _______________________________________________ > > dev mailing list > > [email protected] > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
