You could, however, compare TCP performance with and without a VLAN being involved. Packet loss or out-of-order packets will show up as performance loss.
On Wed, Oct 19, 2011 at 12:14:16PM -0700, Ansis Atteka wrote: > Jesse, > > Potentially we could add iperf TCP tests to the ovs-vlan-test and then IP > packet length would match MTU? Albeit then iperf would not report > packet-loss or out-of-order packet count. > > During the implementation I had following concerns: > > 1. ovs-vlan-test utility uses iperf's STDOUT, STDERR to communicate with > it and that might be iperf-version specific. Preferred approach would be to > use some kind of a "iperf-type"-library, but I was not able to find one > (maybe we could develop one ourselves?). > 2. Iperf also has limitation that smallest UDP packet it can send is > 52-bytes > > > Thanks, > Ansis > > On Wed, Oct 19, 2011 at 11:21 AM, Jesse Gross <[email protected]> wrote: > > > On Tue, Oct 18, 2011 at 9:23 PM, Ansis Atteka <[email protected]> wrote: > > > ovs-vlan-test runs through a number of tests to identify VLAN issues. > > This > > > is useful when trying to debug why a particular driver has issues, but it > > made > > > the testing environment a bit harder to set up. This commit adds an > > iperf > > > test to check basic functionality. It also useful in detecting > > performance > > > issues. > > > > > > Issue #6976 > > > > I didn't review the implementation details but I have some high level > > concerns about the tests being run: > > * At least some of the problems that we have encountered are due to > > offloading and some offloads are only available with TCP. Therefore, > > running only UDP traffic won't catch these. > > * Another category of issues has do with exactly MTU sized packets. > > I see that the packet sizes you use are the same as the previous > > version but I'm not sure that they are great choices. The first issue > > is that it is essentially assuming that the MTU is 1500 but ideally we > > would actually detect it. Once we have it, I would pick a value that > > is exactly MTU size after accounting for the UDP headers. Right now > > we will probably get that but you have to assume that fragmentation > > results in a maximum size first packet. > > > _______________________________________________ > dev mailing list > [email protected] > http://openvswitch.org/mailman/listinfo/dev _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
