Thanks Stephen, I will go back and see what happens happens in a bi-directional test. And yes, we plan on using the firewall capabilities, so I will spend some time looking at what happens when I am running with all the firewall rules loaded. --joubert On 8/28/06, Stephen Hemminger <shemminger at osdl.org> wrote: > On Sun, 27 Aug 2006 10:05:01 -0400 > "Joubert Berger" <joubertb at gmail.com> wrote: > > > I was running a frame loss test the other day against an rhel4 smp > > kernel and a non-smp kernel. I noticed I was getting better numbers > > when I ran the non-smp kernel. I was surprised by that. Anyone have > > any insight into this? I am running this with e1000 dirvers. > > Turning NAPI on/off might change the numbers slightly. > > > I also ran a test where I ran the smp kernel with hyper threading > > turned on and off. There, the frame loss numbers were worse when > > hyper threading was turned off. I would not have thought that having > > hyperthreading turned off would make such a big difference. > > > > Just trying to make sense of these numbers :-) > > > > --joubert > > Forwarding packets is inherently single threaded, the additional CPU's > can't really make it any faster. They can only cause additional cache > misses and locking overhead. The additional CPU's might help if you > performed a bidirectional or multiple interface test. Forwarding packets > shouldn't normally CPU bound, it is limited by the bus and interrupt rate. > If you are doing lots of firewalling that can change. >
