Re: rdma_get_cm_event() vs ibv_async_event()

[Yann Droneaud <ydroneaud-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org>]

Le mardi 29 mars 2011 à 12:14 +0200, Or Gerlitz a écrit :
> 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 used to
> > send the event back to RDMA CM layer. But sometimes, rdma_notify()
> > returns -1 and errno is set to EISCONN : Transport endpoint is already
> > connected. (It happens mostly when I'm running my test program under strace).
> 
> EISCONN means that between the time you've got the comm established 
> 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 
> page says that rdma_notify "handle the rare situation where the 
> connection never forms on its own", so as for your questions, the errno
> you see isn't a failure (see the patch I sent to Sean), and you should
> listen on IB async event and report the comm established for the rare 
> case the kernel can't establish the connection as of repeated CM packet loss
> 

Thanks for the information.

So ignoring IBV_EVENT_COMM_EST async event seems the best option when
using RDMA CM to establish connection ?

Regards.

-- 
Yann Droneaud
OPTEYA


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