On Fri, Apr 08, 2005 at 03:37:32PM -0400, Hal Rosenstock wrote: > Hi Libor, > > A couple of questions about SDP performance: > > 1. When running the AIO version of TTCP, there appears to be a bandwidth > degradation when using buffer sizes from about 5K to 13K. Do you see > this too ? If so, is there an explanation for this ?
This would be the result of transitioning from buffered to zcopy mode at 5K, which is the zcopy threshold. You can change the threshold with a socket option, which is exposed in ttcp.aio.c using the -z option. I was not planning on spending time to determine the correct value of the default threshold until the code stabalized a bit. At this point I'm investigating what appears to be an RDMA going into an incorrect location. > 2. Also, is there a program you use to measure SDP latency ? I've used netperf in the past which has a roundtrip test to measure latency using the regular sockets API. I don't have an AIO latency test handy at the moment, but I could fix one up and place it in the examples directory... -Libor _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
