On Thu, 2018-02-22 at 14:46 +1100, Balbir Singh wrote: <snip> > lpc_size could be added. It's currently useless to the library, but > > doesn't > > hurt. The one which was giving me troubles on a previous version of > > this > > patch was the lpc numa node ID, since that was experimental code > > and felt > > out of place considering what's been upstreamed in skiboot and > > linux so far. > > > > Yeah, I think metadata will evolve for a while till it settle's down. > Since ocxl_ioctl_get_metadata is exposed via uapi, a newer program > calling an older kernel will never work, since the size of that > struct > will always be larger than what the OS supports and our > copy_to_user() > will fail. The other option is for the user program to try all > possible versions till one succeeds, that is bad as well. I think > there are a few ways around it, if we care about this combination. > > Balbir Singh. >
We have a number of reserved members at the end of the struct which can be re-purposed for future information (with a corresponding bump of the version number). -- Alastair D'Silva Open Source Developer Linux Technology Centre, IBM Australia mob: 0423 762 819
