Re: sense remote hardware address change by rdma-cm applications

Steve Wise
2010-07-20T21:03:04Z

Jason Gunthorpe wrote:
> On Tue, Jul 20, 2010 at 03:50:05PM -0500, Steve Wise wrote:
>
>
>>> I think if RDMACM manages the dst and lets the devices access it then
>>> all the existing netdev infrastructure for poking at a dst should be
>>> available to the device?
>>>
>> Yes. But I'm not sure exactly how the logic I described previous for
>> cxgb* would be handled in the design being ironed out here.
>>
>
> I'm thinking something like this..
>
> - The RDMA CM gets the dst from its route lookup locks it and stores
> it.
> - Instead of doing a route lookup cxgb gets the dst from RDMA CM,
> locks it and stores it
> - RDMA CM traps all notifications/etc and generates callback to cxgb
> to say the dst has changed.
> - cxgb releases the old dst and grabs the new one, updates the HW,
> etc.
>
> Basically the same as what you have now, but all the logic to find
> and monitor the dst moves to RDMA CM..
>
> redirects/etc are all handled by netdev/rdma cm and just generate the
> same 'dst has changed' call back to cxgb..
>
> Or's user space notification stuff hooks the same callback to generate
> a notification to userspace about the new dst.
>
> All the stuff you do now with the dst you can keep doing, you just
> remove all the route lookup and netdev hooking to get the dst from
> RDMA CM.
>
> Jason
>

Sounds like this would work nicely.

Steve.