Re: [PATCH v4 4/4] IB/sa: Route SA pathrecord query through netlink

Hal Rosenstock
2015-06-10T19:51:54Z

On 6/10/2015 3:10 PM, Jason Gunthorpe wrote:
> On Wed, Jun 10, 2015 at 01:47:36PM -0400, Hal Rosenstock wrote:
>> On 6/9/2015 10:57 AM, kaike.wan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote:
>>> From: Kaike Wan <kaike.wan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>>>
>>> This patch routes a SA pathrecord query to netlink first
>>
>> Should only unicast PRs be done in this manner or should API support
>> enabling for unicast and/or multicast ?
>>
>> AFAIK kernel doesn't query multicast PRs now (queries MCMRs) but this
>> seems like it would help make it future proof and not have to take
>> timeout on local query unless app supports it.
>
> It is a good question. We can clearly extend toward that, using a MGID
> as the DGID and adding additional nested netlink fields.
>
> However, does it make sense?

If it doesn't make sense, then should MGIDs as DGIDs never be requested
via the PR netlink API ?

> I don't think user space should be
> joining on behalf of the kernel...

Agreed.

> Do we ever query without a join?

Query is possible prior to join.

The use case I'm aware of is doing query PR for MGID rather than query
MCMR. That case could be viewed just like unicast PRs.

-- Hal

> Jasno