On Mon, Feb 20, 2012 at 18:34, Adrian Chadd <adr...@freebsd.org> wrote: > Is the target though _binary_ compatibility? Just having a blessed > method of doing accessor method things will buy more source > flexibility. The KBI can stay the same in the default case and IMHO > this kind of thing gives developers more power to do smart invariant > and debugging things.
KBI compatibility requires very little discipline and makes loadable modules for network drivers much less hellish. Inlines, macros and full visibility of ifnet in -current may be useful, but unless there's a performance reason for doing so, retaining KBI compatibility *and* the ability to merge ifnet changes to -stable sounds pretty nice to me. > Being able to say "inform me every time an interface flag changes" > would actually be kind of nice when debugging some of the issues i've > been facing with ath. I've been half tempted to do this -inside- the > ath driver, partially to restore the OS portability it once tried to > achieve. I think that it is rare that this is useful in debugging, and something of a red herring. Even invariants are almost a red herring: really, we shouldn't be using these individual methods to tweak structure fields, either, we should have a way of describing a network driver more semantically, such that the invariants are richer and also not as complicated, and also more comprehensive. Source compatibility is the biggest win, but a little self-discipline to win what measure of binary compatibility we can seems perfectly sensible. (And at some point, we could even replace ifnet with something that's less of a strange grab bag assortment that's awkward to explain to new driver writers, and keep both source and binary compatibility for a reasonable period in doing so. Unlikely to happen in the near term, but wouldn't it be nice? _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
