On Wed, Jan 22, 2014 at 05:35:40PM +0000, McGarvey, Kevin wrote: > > > On 1/21/14 6:17 PM, "Ben Pfaff" <b...@nicira.com> wrote: > >I'd expect a dramatic drop in CPU consumption in that case. There are > >a few special cases where the upgrade wouldn't help. One is if > >in-band control is in use, another is if NetFlow is turned on, a third > >is if LACP bonds with L4 port based hashing are turned on, and there > >are probably a few others that don't come to mind immediately. > > I plan to rerun the test to rule out some mistake on my part. > > Could you provide more information about the nature of the change made in > 1.11 that improves performance for this type of traffic? Is the kernel > module able to forward UDP DNS packets without sending them to userspace, > or was it an optimization of the userspace processing? What roughly is > the level of performance I should see?
In 1.11 and later, for simple OpenFlow tables (I don't think you mentioned whether you are using a controller or which one), Open vSwitch can set up only a single kernel flow that covers many possible flows, for example all possible UDP destination ports, rather than setting up an individual kernel flow for each UDP packet. When that works, it eliminates most of the kernel/userspace traffic, improving performance. Version 2.0 is better at analyzing OpenFlow flow tables to see when this is possible, so it can better take advantage of the ability. _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
