On Friday, May 31, 2019 10:47:21 AM CEST Jiri Kosina wrote: > On Fri, 31 May 2019, Josh Poimboeuf wrote: > > > > I disagree with that from the backwards compatibility point of view. > > > > > > I personally am quite frequently using differnet combinations of > > > resumer/resumee kernels, and I've never been biten by it so far. I'd > > > guess > > > I am not the only one. > > > Fixmap sort of breaks that invariant. > > > > Right now there is no backwards compatibility because nosmt resume is > > already broken. > > Yeah, well, but that's "only" for nosmt kernels at least. > > > For "future" backwards compatibility we could just define a hard-coded > > reserved fixmap page address, adjacent to the vsyscall reserved address. > > > > Something like this (not yet tested)? Maybe we could also remove the > > resume_play_dead() hack? > > Does it also solve cpuidle case? I have no overview what all the cpuidle > drivers might be potentially doing in their ->enter_dead() callbacks. > Rafael?
There are just two of them, ACPI cpuidle and intel_idle, and they both should be covered. In any case, I think that this is the way to go here even though it may be somewhat problematic to start with. Cheers, Rafael
