Long-term we'll probably end up with the console in userspace, which should naturally normalize scrollback behavior across all the kms drivers.
There's already kmscon but I haven't looked closely into what prevented that transition from moving forward as the default. Presumably there's a bunch of edge cases a kernel based console doesn't suffer from, like having to avoid oom killer or getting paged out/becoming unresponsive on systems falling over etc.
The console process will have to be something exceptionally configured, pinned memory, realtime priority, oom-immune, all that jazz.
Not really. Most of such a system can just be ordinary processes, and there's no requirement for pinned memory anywhere. Pretty much only the terminal emulator processes are problems if they die, as that effectively becomes a hangup signal, so only they need the oom immunity, if that.
There's already kmscon but I haven't looked closely into what prevented that transition from moving forward as the default. Presumably there's a bunch of edge cases a kernel based console doesn't suffer from, like having to avoid oom killer or getting paged out/becoming unresponsive on systems falling over etc.
The console process will have to be something exceptionally configured, pinned memory, realtime priority, oom-immune, all that jazz.