[RFC v1 0/3] Unifying fabrics drivers

[Sagi Grimberg]

On 3/7/23 14:28, Daniel Wagner wrote:
> On Tue, Mar 07, 2023 at 11:26:12AM +0200, Sagi Grimberg wrote:
>> I think we should make all transports to unify setup/teardown sequences
>> (i.e. including pcie and fc). Otherwise we are not gaining much.
> 
> Not sure about pcie but I haven't really looked at it. The state machine is
> really handling all the fabrics specific queue handling.
> 
> Ideally, fc would use the same state machine. Though the current code base is
> differs quiet significantly but I can try to convert it too.
> 
>> It will help if we make the ops higher level like
>>
>> ops.setup_transport(ctrl)
>> ops.alloc_admin_queue(ctrl)
>> ops.start_admin_queue(ctrl)
>> ops.stop_admin_queue(ctrl)
>> ops.free_admin_queue(ctrl)
>> ops.alloc_io_queues(ctrl)
>> ops.start_io_queues(ctrl)
>> ops.stop_io_queues(ctrl)
>> ops.free_io_queues(ctrl)
> 
> This is more ore less what v2 is.
> 
>> The init/deinit can be folded to alloc/free I think.
> 
> Yes, that would a good thing. In my first attempt I tried to keep things more a
> less identically with the existing code, just using the callbacks for the
> transport specific bits.
> 
>> This is indeed a much larger effort, but I don't know what
>> this unification of rdma/tcp buys us really...
> 
> My motiviation is that we are keep fixing the same bugs in rdma and tcp
> transport since a while. The state machine code is almost identically so why not
> trying to reduce the code duplication?

I'm not saying that we shouldn't, I'm saying that we should consolidate
with all transports (rdma/fc/tcp/loop and ideally also pcie which is
closer to fabrics than what it used to be).