Unexpected issues with 2 NVME initiators using the same target

[Chuck Lever]

> On Jun 27, 2017, at 3:37 AM, Sagi Grimberg <sagi at grimberg.me> wrote:
> 
> Jason,
> 
>>> The issue about the HCA not being able to access the inline
>>> buffer during a retransmit is also not an issue for RPC-
>>> over-RDMA because these buffers are always registered with
>>> the local rdma lkey.
>> Exactly.
> 
> Lost track of the thread...
> 
> 
> Indeed you raised this issue lots of times before, and I failed to see
> why its important or why its error prone, but now I do...
> 
> My apologies for not listening :(
> 
> We should fix _all_ initiators for it, nvme-rdma, iser, srp
> and xprtrdma (and probably some more ULPs out there)...

Go back and browse the end of the thread: there's no need to change
xprtrdma, and maybe no need to change the others either.


> It also means that we cannot really suppress any send completions as
> that would result in an unpredictable latency (which is not acceptable).
> 
> I wish we could somehow tell the HCA that it can ignore access fail to a
> specific address when retransmitting.. but maybe its too much to ask...

--
Chuck Lever