Hi everybody! We are currently migrating to kernel 2.6.3 on our MPC8260 custom board. The porting has been successfully completed. Nevertheless we are facing some performance problems.
The board is to be impement layer 3 routing (over Ethernet) functionality. Here is the description of the problem. We are testing the layer 3 routing performance of the board. When we try to route let's say 300,000 packets over a certain time period through the processor , it is not able to handle all the load and only routes around 200,000 packets. This is fine and is due to the processor/software limitations. This shows however that the "routing limit" of the processor is around 200,000. The strange thing that happens is that when we try to route a smaller amount of data e.g 100,000 packets, the processor still cannot manage to route all of them and still routes only 90,000 packets. My question is why does the proccessor refuses to route 100,0000 (or even less) packets since it is able to route much more packets (200,000) over the same period of time. The same set of tests has been performed on the board using a 2.4.20 kernel. The results were more predictable. Again when we try to route 300,000 packets over a certain period of time the processor routes only around 200,000 (this is its limit). But when we try to route 180,000 packets, the processor routes them all fine. At the time of the test the processor in not loaded with any other tasks. Any advice will be greatly appreciated. Thanks! Stergios. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
