> Ugh. OFED 1.2 (with the old ABI) just went out. > I wonder - is it time to start making the kernel backwards-compatible? > It would be trivial to have userspace supply its own ABI > version and have kernel support both new and old ABI if we want to. > What do you think?
There's always a balance between keeping cruft in the kernel for compatibility and not breaking userspace. I'm beginning to think the right plan in this case might be to rename struct ib_user_mad_hdr to struct ib_user_mad_hdr_old, make a new struct ib_user_mad with the pkey_index member and add a new ioctl IB_USER_MAD_ENABLE_PKEY_INDEX. The ABI version would stay the same, and if someone just opened the device and didn't do the IB_USER_MAD_ENABLE_PKEY_INDEX they would get the old ABI. If they do the ioctl then they get the new header. Also we could define that ABI version 6 just has the new struct ib_user_mad_hdr and no ioctl. Then we could say we were going to switch to the new ABI in a year or two. And print a warning in the kernel log for every application that doesn't use the ioctl. I'll try to cook up a kernel patch next week. - R. _______________________________________________ general mailing list general@lists.openfabrics.org http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
