RE: [PATCH v5 1/4] IB/netlink: Add defines for local service requests through netlink

Wan, Kaike
2015-06-12T00:28:44Z

> From: Jason Gunthorpe [mailto:jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org]
> Sent: Thursday, June 11, 2015 8:22 PM
> To: Wan, Kaike
> Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Fleck, John; Weiny, Ira
> Subject: Re: [PATCH v5 1/4] IB/netlink: Add defines for local service requests
> through netlink
>
> On Thu, Jun 11, 2015 at 11:45:46PM +0000, Wan, Kaike wrote:
> > Apparently, to achieve this goal, we need the following changes:
>
> I don't expect anything more than a proper hole in the UAPI to make this
> work.
>
> I already have patches that implement full kernel support for the 6-path
> format, and globally enable APM. With this netlink interface it becomes
> feasible to mainline them. That will require some reworking of what you've
> done, but I don't expect you to do that.
>
> The only remaining thing we need here is that tiny bit of policy information
> for the kernel to specify what the intended use of the path is:
> - For connected CM operation (6 path records)
> - For unidirectional UD (1 path record)
> - For 'misc' GMP like operation (at least 1 reversible path record)
>
> I'm happy if you call it PATH_USE_XX
>
> Testing the reversible bit should be enough to rough this in, if not reversible it
> is PATH_USE_UNIDIRECTIONAL_UD, otherwise it is PATH_USE_GMP.
>
> Recommend that userspace treat any unknown usage type as GMP (it is the

> most general).

That would be cool. If we add this attribute, should we remove reversible and numb_path attributes?

Kaike

>
> Ira: Do you like 'path use' better as a name? I think I do..
>
> Jason