From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann Droneaud Subject: Re: rdma_get_cm_event() vs ibv_async_event() Date: Tue, 29 Mar 2011 12:33:35 +0200 Message-ID: <1301394815.2193.2.camel@deela.quest-ce.net> References: <1301052615.2192.15.camel@deela.quest-ce.net> <1301059658.2192.23.camel@deela.quest-ce.net> <1301391461.2192.41.camel@deela.quest-ce.net> <4D91B107.2040007@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4D91B107.2040007-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Or Gerlitz Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Hefty, Sean" List-Id: linux-rdma@vger.kernel.org Le mardi 29 mars 2011 =C3=A0 12:14 +0200, Or Gerlitz a =C3=A9crit : > Yann Droneaud wrote: > > [...] I caught and handle is IBV_EVENT_COMM_EST because it > > happen sometimes under high load. In this case, rdma_notify() is us= ed to > > send the event back to RDMA CM layer. But sometimes, rdma_notify() > > returns -1 and errno is set to EISCONN : Transport endpoint is alre= ady > > connected. (It happens mostly when I'm running my test program unde= r strace). >=20 > EISCONN means that between the time you've got the comm established=20 > async event to the time you reported on it by calling rdma_notify, > the kernel CM managed to establish the connection. Note that the man=20 > page says that rdma_notify "handle the rare situation where the=20 > connection never forms on its own", so as for your questions, the err= no > you see isn't a failure (see the patch I sent to Sean), and you shoul= d > listen on IB async event and report the comm established for the rare= =20 > case the kernel can't establish the connection as of repeated CM pack= et loss >=20 Thanks for the information. So ignoring IBV_EVENT_COMM_EST async event seems the best option when using RDMA CM to establish connection ? Regards. --=20 Yann Droneaud OPTEYA -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html