At 03:41 PM 2/7/2007, Roland Dreier wrote: > Changqing> What I mean is that, is there any performance penalty > Changqing> for receiver's overall performance if RNR happens > Changqing> continuously on one of the QP ? > >Not for the receiver, but the sender will be severely slowed down by >having to wait for the RNR timeouts.
RNR = Receiver Not Ready so by definition, the data flow isn't going to progress until the receiver is ready to receive data. If a receive QP enters RNR for a RC, then it is likely not progressing as desired. RNR was initially put in place to enable a receiver to create back pressure to the sender without causing a fatal error condition. It should rarely be entered and therefore should have negligible impact on overall performance however when a RNR occurs, no forward progress will occur so performance is essentially zero. Mike _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
