[ovs-discuss] poor performance after adding vlan tag to a vport

[Hui Kang]

Hi, Justin,
Thanks for your suggestions. My concern is that vlan works for my test
cases and no packet drops with the iperf TCP test. However, the problem is
about performance loss compared to no vlan tag is set on the vport.

Regarding vlan splinter, the FAQ says "VLAN splinters increase memory use
and reduce performance, so use them only if needed." So I guest it will not
improve the throughput performance.

Anyway, I will try a different kernel version and see if it improves.

- Hui

On Tue, Apr 29, 2014 at 5:47 PM, Justin Pettit <jpettit at nicira.com> wrote:

> I'd try taking a look at the FAQ, which discusses VLANs quite a bit.  In
> particular, you may want to try the VLAN Splinters workaround.
>
> --Justin
>
>
> On April 29, 2014 at 2:36:23 PM, Hui Kang (hkang.sunysb at gmail.com) wrote:
> > Hi, Justin,
> > I used OVS 1.9.3. But there is nothing suspicious in the log when I grep
> > for vlan in the log file.
> >
> > - Hui
> >
> >
> > On Tue, Apr 29, 2014 at 5:28 PM, Justin Pettit wrote:
> >
> > > On April 29, 2014 at 2:26:18 PM, Hui Kang (hkang.sunysb at gmail.com)
> wrote:
> > > > Hi,
> > > > I use iperf to test the 10G performance of OVS bridge with vlan tag
> added
> > > > on the vport for the VMs.
> > > >
> > > > On each machine, the OVS bridge are created on the Intel 82599 10G
> NIC. I
> > > > found the performance drops significantly when I added vlan tag on
> the
> > > > vport of both VMs.
> > > >
> > > > no vlan tag: 9.47 Gbps
> > > > add vlan tag: 3.96 Gbps
> > > >
> > > > Is this a normal behavior after adding vlan tag to the packet header?
> > >
> > > I don't think that should be happening. What version of OVS are you
> > > running? Do you see anything suspicious in your ovs-vswitchd.log?
> > >
> > > --Justin
> > >
> > >
> > >
> > >
> >
>
>
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