Re: [Qemu-devel] Enabling vhost-net cause insane high memory usage.

[Piotr Karbowski]

On 01/15/2014 10:36 PM, Piotr Karbowski wrote:
> Hello,
>
> On 01/15/2014 11:03 AM, Michael S. Tsirkin wrote:
> > Could you explain how you measure that exactly?
>
> I check the resident memory (RES) of qemu-system-x86_64 proces.
>
>
> > Yes, this should not happen.
> > One interesting thing to try would be switching device type from
> > virtio-net to e1000.
> >
> > This means vhost will be initialized but not started.
>
> So with virtio-net-pci + vhost=on I have VM process on 580-590 MB of RES
> memory, if I disable vhost OR set e1000 NIC and leave vhost enabled, its
> take just 109-120 MB of resident memory.
>
> The memory usage check is done after few minutes after VM start, and the
> vm have minimal debian7 system without even single additional service.

Quick note, the test was done on VM with 512 MB memory set, if I test it 
on the 2 GB one, RES with vhost-enabled virtio-net-pci goes a bit above 
2 GB shortly after start.

-- Piotr.