On Mon, 17 Jul 2023 at 10:45, Simon Ser <contact@xxxxxxxxxxx> wrote: > > On Monday, July 17th, 2023 at 09:30, Emil Velikov <emil.l.velikov@xxxxxxxxx> wrote: > > > > I'm worried what might happen with old user-space, especially old libdrm. > > > > I also share the same concern. Although the bigger issue is not libdrm > > - since we can update it and prod distributions to update it. > > The biggest concern is software that cannot be rebuild/updated - > > closed source and various open-source that has been abandoned. > > Well. Now that we have Flatpak and AppImage and friends, we're really likely > to have old libdrm copies vendored all over the place, and these will stick > around essentially forever. > The flatpak devs have been very helpful. So I'm pretty sure we can get those updated - even for older flatpaks. For AppImage, I have no experience. > > For going forward, here is one way we can shave this yak: > > - update libdrm to max 64 nodes > > - roll libdrm release, nag distributions to update to it // could be > > folded with the next release below > > - update libdrm to use name driven type detection > > - roll libdrm release, nag distributions to update to it > > - once ^^ release hits most distributions, merge the above proposed > > kernel patch > > - the commit message should explain the caveats and fixed libdrm version > > - we should be prepared to revert the commit, if it causes user > > space regression - fix (see below) and re-introduce the kernel patch > > 1-2 releases later > > That sounds really scary to me. I'd really prefer to try not to break the > kernel uAPI here. > With part in particular? Mind you I'm not particularly happy either, since in essence it's like a controlled explosion. > The kernel rule is "do not break user-space". Yes, in a perfect world. In practice, there have been multiple kernel changes breaking user-space. Some got reverted, some remained. AFAICT the above will get us out of the sticky situation we're in with the least amount of explosion. If there is a concrete proposal, please go ahead and sorry if I've missed it. I'm supposed to be off, having fun with family when I saw this whole thing explode. Small note: literally all the users I've seen will stop on a missing node (card or render) aka if the kernel creates card0...63 and then card200... then (hard wavy estimate) 80% of the apps will be broken. HTH Emil
