[libfabric-users] suggested multi-recv feature enhancement

[Hefty, Sean]

> It would be nice if there was a fi_setopt() variable for multi-recv buffers, say
> FI_MIN_MSG_ALIGNMENT, which the application could set to 8 or whatever, guaranteeing
> that as libfabric lands new messages into the multi-recv buffer that they would be
> aligned on 8-byte boundaries, so that an application could safely reference metadata
> messages in-place in the multi-recv buffer without segfaulting, avoiding constant
> memcpy calls.

The API already allows the provider to perform alignment as needed, so I don't see any issue with supporting get/set calls to discover and, possible, set this.  The app would still need to handle fi_setopt() failing if the alignment can't be supported.  This would likely need to be set early on, maybe before an EP is enabled.

- Sean