[ofa-general] Re: NOSRQ misc patch [PATCH V1]

[Pradeep Satyanarayana]

Michael S. Tsirkin wrote:
>> Quoting Pradeep Satyanarayana <pradeeps at linux.vnet.ibm.com>:
>> Subject: Re: NOSRQ misc patch [PATCH V1]
>>
>> Michael S. Tsirkin wrote:
>>>> @@ -1168,9 +1170,9 @@ static struct ib_qp *ipoib_cm_create_tx_
>>>>  	attr.recv_cq = priv->cq;
>>>>  	attr.srq = priv->cm.srq;
>>>>  	attr.cap.max_send_wr = ipoib_sendq_size;
>>>> -	attr.cap.max_recv_wr = 1;
>>>> +	attr.cap.max_recv_wr = 0;
>>>>  	attr.cap.max_send_sge = 1;
>>>> -	attr.cap.max_recv_sge = 1;
>>>> +	attr.cap.max_recv_sge = 0;
>>>>  	attr.sq_sig_type = IB_SIGNAL_ALL_WR;
>>>>  	attr.qp_type = IB_QPT_RC;
>>>>  	attr.send_cq = cq;
>>> I don't see how does this fix things.
>>> This line 
>>>>  	attr.srq = priv->cm.srq;
>>> connected the TX QP to SRQ, making it possible to get packets on this QP.
>>> But if cm.srq is NULL, and a remote sends a packet on this connection,
>>> the connection will get closed. Which is a quality of implementation issue.
>>>
>> When the QP numbers are exchanged correctly, then it should not receive
>> a packet on this QP in the first place.
> 
> Re-read the RFC. It is perfectly legal to reuse a passive QP for transmitting
> packets. We don't do this currently but we might in the future.

I presume you mean passive side for receiving. Let us revisit the issue when there
is a need. At this point it is not relevant.

Pradeep