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? I plan to review your patches. Thanks, Jan > -----Original Message----- > From: [email protected] > [mailto:[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
