> From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma- > owner@xxxxxxxxxxxxxxx] On Behalf Of Hefty, Sean > Sent: Tuesday, November 21, 2017 6:27 PM > To: Kalderon, Michal <Michal.Kalderon@xxxxxxxxxx>; Jason Gunthorpe > <jgg@xxxxxxxx>; linux-rdma@xxxxxxxxxxxxxxx > Cc: Elior, Ariel <Ariel.Elior@xxxxxxxxxx>; Amrani, Ram > <Ram.Amrani@xxxxxxxxxx>; Radzi, Amit <Amit.Radzi@xxxxxxxxxx> > Subject: QPN re-use? was RE: rstream application > > > Rstream client connects to server, runs latency test, calls rs_close > > and then connects Again before running the bandwidth test. The issue > > occurs on the second connect (after latency and before bandwidth). > > Server does the same. It seems the close state in some cases doesn't > > complete Before the second connect request arrives. > > Yes, the hardware re-uses QPNs once they are destroyed. > > If the issue is that the QP is in time wait, I'm not sure this is completely an > application issue. The QP being re-used could have been allocated by > another application, with timewait being set to something large. This > wouldn't be an rstream issue, but something all applications would be > required to handle. > > It sounds like there needs to be some sort of coordination of QPN re-use > between the drivers and CM, especially if the driver wants to re-use QPNs as > LIFO. Thanks, Sean. This makes sense. So are you suggesting and additional API between CM And driver to notify when a QPN can be re-used ? Just to emphasize though, the problem could still occur if on client side the QPN is released After timewait, but timewait didn't pass on server-side. (this is similar to the case here, The QPN re-use was on the client side, where the connection was no longer in time-wait, but Existed in the server side remote-qp tables ). Thanks, Michal > > - Sean > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the > body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at > http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
