On Tuesday, 13 March 2007 11:31, Nick Piggin wrote: > Rafael J. Wysocki wrote: > > On Tuesday, 13 March 2007 10:23, Nick Piggin wrote: > > > > >>I wouldn't say that. You're creating an interface here that is going to be > >>used outside swsusp. Users of that interface may not need locking now, but > >>that could cause problems down the line. > > > > > > I think we can add the locking when it's necessary. For now, IMHO, it could be > > confusing to someone who doesn't know the locking is not needed. > > I don't know why it would confuse them. We just define the API to > guarantee the correct locking, and that means the locking _is_ needed. Even if there are no users that actually need the locking and probably never will be? For now, register_nosave_region() is to be called by architecture initialization code _only_ and there's no reason whatsoever why any architecture would need to call it concurrently from many places. > You don't have to care what the callers are doing. That's the beauty > of a sane API. Well, I don't think adding unneded infrastructure is a good thing. > >>Sure you don't _need_ an rbtree, but our implementation makes it so simple > >>that there isn't much downside. > > > > > > Not much, but the code is more complicated. > > But it's in its own file and has a contained API, so it is very easy > to review, test and verify. I'm still thinking that register_nosave_region() in its current form is simpler and easier to review than the code using rbtrees. Still, of course this only is my personal opinion. :-) > >>>mark_nosave_pages() refers to a function that's invisible outside snapshot.c > >>>and I didn't think it was a good idea to separate mark_nosave_pages() > >>>from register_nosave_region(). > >> > >>But that's because you even use mark_nosave_pages in your implementation. > >>Mine uses the nosave regions directly. > > > > > > Well, I think we need two bits per page anyway, to mark free pages and > > pages allocated by swsusp, so using the nosave regions directly won't save us > > much. > > Well I think it is a cleaner though. This is a matter of opinion, too ... Greetings, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxx https://lists.osdl.org/mailman/listinfo/linux-pm
