[ewg] RE: RFCv2: SRC API

[Tang, Changqing]

> > I have another question, when using SRQ, or SRC+SRQ, when a 
> completion 
> > is returned by ibv_poll_cq(),  is there an easy way to find 
> who sent 
> > this message to me ? 'struct ibv_wc' does not say much about the 
> > message source rank. The only field is 'src_qp', but I can not find 
> > any document about how to use it.
> 
> There's also qp_num.

1. src_qp is 'uint32_t', what does it mean ? Translate 'src_qp/qp_num'
to source info is not easy, right ?

2. for SRC+SRQ, these two fields are not useful, because if a rank is
not the rank who made connection (j3,j4, not j2, as we discussed), it
has no information about the send QP.


> 
> > Is there any way to return some kind of "source context" ?
> > 
> > Or do you think this is application's responsibility to figure out 
> > source rank from the message itself ? I hope the source rank can be 
> > identified before parsing the message.
> > 
> > Thanks.
> 
> How about using send with immediate, and sticking the rank in 
> the immediate data?

I always think 'send-with-immediate' is slower than 'send', am I wrong ?
Anyway this is the best way so far.

--CQ


> 
> --
> MST
>