I assume there is a leak somewhere on adding/removing vhost_user ports. Although it could also be "only" a fragmentation issue.
Reproduction is easy: I set up a pair of nicely working OVS-DPDK connected KVM Guests. Then in a loop I - add up to more 512 ports - test connectivity between the two guests - remove up to 512 ports Depending on memory and the amount of multiqueue/rxq I use it seems to slightly change when exactly it breaks. But for my default setup of 4 queues and 5G Hugepages initialized by DPDK it always breaks at the sixth iteration. Here a link to the stack trace indicating a memory shortage (TBC): https://launchpadlibrarian.net/253916410/apport-retrace.log Known Todos: - I want to track it down more, and will try to come up with a non openvswitch based looping testcase that might show it as well to simplify debugging. - in use were Openvswitch-dpdk 2.5 and DPDK 2.2; Retest with DPDK 16.04 and Openvswitch master is planned. I will go on debugging this and let you know, but I wanted to give a heads up to everyone. In case this is a known issue for some of you please let me know. Kind Regards, Christian Ehrhardt Software Engineer, Ubuntu Server Canonical Ltd P.S. I think it is a dpdk issue, but adding Daniele on CC to represent ovs-dpdk as well.
