[ofa-general] retry exceeded problem with rdma_read

[Rajouri Jammu]

I have the following set both on rdma_connect as well as at rdma_accept.
        conn_param.responder_resources = 4;
        conn_param.initiator_depth = 4;

Should initiator_depth be lower for better behavior?



On Jan 9, 2008 10:16 PM, Dotan Barak <dotanb at dev.mellanox.co.il> wrote:

> Rajouri Jammu wrote:
> > Occasionally, I'm getting a retry exceeded error on the qp (error 12)
> > when doing rdma_reads.
> >
> > Under what conditions would thins kind of problem happen?
> >
> > I have the retry_count = 5 and 'am using rdma_cm for all the
> > connection setup.
> >
> > OFED version is 1.2.5
> Does it happen between different HCAs?
>
> If this happens during working with the QPs (not in the first message)
> than check the following thing:
>
> If the QP attributes values of  max_rd_atomic and max_dest_rd_atomic
> this may happen.
>
> The values should be (for sides A and B):
> A.max_rd_atomic         <= B.max_dest_rd_atomic
> A.max_dest_rd_atomic >= B.max_rd_atomic
>
> (which means that RDMA Reads/atomic as initiator shouldn't be larger
> than the supported value as the destination)
>
> You can check it by query the used QP and verify those values.
>
>
>
> If it happens at the beginning of the connection, there may be other
> problem and i need more info  ....
>
> Dotan
>
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