[ovs-discuss] Info about OVS kernel module

[Jesse Gross]

On Mon, Feb 13, 2012 at 9:04 AM, Syed Abdullah Shah
<08beeabshah at seecs.edu.pk> wrote:
>
> Hi,
> We are running some tests for which we require multiple OVSs to be deployed
> in the network. I want to clarify some things before we proceed.
> Is there multi-threading employed in the OVS kernel module? I mean If
> we have a cpu containing 16 cores can we run 16 separate ovs kernel
> modules so that essentially each core can act like an OVS? I know we
> can create multiple bridges on top of a single OVS kernel but that will
> be essentially one OVS. Please guide me in this and please correct me
> If I am perceiving things wrong. What we want is that multiple OVS instances
> should be running on multiple cores. Is it possible ? If not do we need a
> separate CPU or a VM for each OVS instance ?

Packets are processed by the network stack (including OVS) inline on
the CPU that the are received by the kernel.  This means that on
receive the CPU is determined by the NIC's ability to spread traffic
around and on transmit by the hypervisor.  Creating additional
instances of OVS has no effect on what core packets are processed on.