Re: Memory leak when adding/removing vhost_user ports

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Mon, Apr 18, 2016 at 07:18:05PM +0200, Christian Ehrhardt wrote:
> 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.

Thanks for the report.

> In case this is a known issue for some of you please let me know.

Yeah, it might be. I'm wondering that virtio_net struct is not freed.
It will be freed only (if I'm not mistaken) when guest quits, by far.

BTW, could you dump the ovs-dpdk log?

	--yliu