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

Jason Gunthorpe
2015-06-12T00:21:33Z

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).

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

Jason