[ofa-general] Re: CMA can't establish connection with QoS on

[Yevgeny Kliteynik]

Sean Hefty wrote:
>> I'm having troubles with using rdma when QoS is enabled on the subnet.
>> Everything works fine as long as QoS policy enforces SL=0, but when
>> the policy defines SL!=0, the client application hungs.
>>
>> The only thing I see is that CMA sends sends PathRecord query to OpenSM
>> and OpenSM returns the QoS-enforced SL.
>>
>> I've also opened bugzilla bug for this - num. 821
>> You can see more details and instructions to reproduce it there.
> 
> I haven't tried to reproduce this yet, but looking at the code:
> 
> I didn't notice anything that either the rdma_cm or ib_cm did differently based
> on the value of the SL.  The rdma_cm doesn't do anything with SL except pass
> whatever it gets in the path record through to the ib_cm.  The ib_cm copies the
> SL into the REQ, but it does end up being used to create an address handle to
> send the MAD.  Is there any chance that the creation of the address handle is
> causing the problem?  Does any other QoS related code with SL != 0 work?

Not sure if it helps, but "ibv_rc_pingpong -l <any SL>" works.

-- Yevgeny

> - Sean
>