Am 03.10.2010 09:34, prakash srinivasan wrote: > Dear All, > > I am executing an simple server program using RTNet and test the time > duration to transfer simple "Hello server" message 1000 times from the normal > Linux OS to the real time server. In this case, server program is running by > xenomai and using rtnet network driver. On client side normal linux os > sending the datas and accepting the acknowledgement from the server. For 1000 > loops, its taking 253570us. Average is 253 us. > > However, I am doing the same test using normal linux with normal network > driver on the same network card, its taking only 87us for 1000 loops. > > As the test result shows the real time server using xenomai, RTnet driver > performance is very poor compare with normal network driver. I believe that, > I have some issues in rtnet/xenomai configurations. What are factors I must > consider to reducing the time for sending/receiving the datas?. Any kind of > help is appreciated. > > > > FYI, I am using RTL8139 network card. >
There are a few aspects that could explain the difference: - RTnet's old 8139 driver assumes that the hardware can only do DMA into a small window, thus bounce-copies packets. Linux may use 8139cp instead. Better choose a more modern NIC that RTnet supports as well. - RTnet does one IRQ per packet (unless they arrive in a burst), Linux may try to throttle IRQs via NAPI. The latter is good for throughput and performance, the former can help to lower latencies. - The might be configuration differences in both setups. Are any debugging features of I-pipe and/or Xenomai enabled? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux ------------------------------------------------------------------------------ Virtualization is moving to the mainstream and overtaking non-virtualized environment for deploying applications. Does it make network security easier or more difficult to achieve? Read this whitepaper to separate the two and get a better understanding. http://p.sf.net/sfu/hp-phase2-d2d _______________________________________________ RTnet-users mailing list RTnet-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rtnet-users
