[ovs-dev] [PATCH v2 1/2] Check and allocate free qdisc queue id for ports with qos parameters

[Babu Shanmugam]

On Monday 06 June 2016 08:30 PM, Ben Pfaff wrote:
> On Mon, Jun 06, 2016 at 02:31:03PM +0530, Babu Shanmugam wrote:
>> On Saturday 04 June 2016 01:17 AM, Ben Pfaff wrote:
>>> On Wed, May 25, 2016 at 03:35:44PM +0530, bschanmu at redhat.com wrote:
>>> I'm a little worried about the way that this will re-set all of the
>>> queues on every iteration through the ovn-controller main loop.  That
>>> could have some performance drawbacks.  However, maybe it's not worth
>>> worrying about it until it's a real problem in practice.
>> I think setup_qos() does not touch the queues whose parameters are
>> consistent with the qos_settings on the logical_port.
>> It will modify the queues only when there is a change in the logical_ports.
> You're right.
>
> It does still go to the kernel to dump all the queues, which is the
> expensive part in the common case.  I guess I won't worry about it until
> it's a problem.
>
>>> This patch makes ovn-controller configure queues directly on the egress
>>> interface.  That is completely fine.  However, it means that if the
>>> egress interface is on an OVS bridge (which is often reasonable,
>>> especially if bonding is involved), then ovs-vswitchd will fight with
>>> ovn-controller for control of the queues.  This is a long-time issue in
>>> ovs-vswitchd, and there has been previous discussion:
>>>          http://openvswitch.org/pipermail/discuss/2015-May/017687.html
>>> (Currently, I favor the solution proposed there of adding a new QoS
>>> type.)
>> I too feel that new Qos type is a better solution. I could not locate the
>> code which handles the new type, is it already available?
> None of the solutions presented there has been implemented.
I will include a new Qos type in the v3 version of this patch.
>>> I don't think it's a good assumption that all the tunnels share the same
>>> egress interface.
>> I agree to this. So, we now have to set queues on all possible egreess
>> interfaces. Is my understanding correct?
> Yes.

Thank you,
Babu