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

Steve Wise
2010-07-20T21:15:22Z

Steve Wise wrote:
> 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.
>

Need to hear from Intel. CCing Chien.