All GNU/Linux distributions I tested so far have the problem that whenever the ram gets filled and the system begins swapping, the whole desktop and graphical user interface becomes unresponsive as hell to an extent that sometimes I have to wait about 5-10 seconds after having moved the physical mouse until the mouse pointer is actually moving.
This is kind of an annoying behaviour, especially on systems with low ram.
Is there any way to give some applications/jobs, like the desktop environment etc., a higher priority to stay in ram than other applications, so that the application actually hogging all the memory gets swapped before the desktop environment etc.?
EDIT: I'm talking of the case when the entire RAM is used so it will always start swapping if it isn't disabled (I don't want processes to be killed randomly). I had this problem not only in low ram environments, but as well with 8GiB of ram on my desktop machine, partly due to many VMs partly because of memory leakage. ZRAM isn't a solution either as it's only delaying the problem. The only solution I can think of for this problem is some userspace utility or kernel API that allows to prevent certain jobs to be swapped at all or at least make it very unlikely. Does anybody know another solution or knows anything about such a tool or API in existence or being planned?
2nd EDIT: ulatencyd doesn't seem to work with newer versions of systemd, according to https://aur.archlinux.org/packages/ulatencyd-git/ and https://wiki.archlinux.org/index.php/Ulatencyd . This may be because systemd took over full control of cgroups from a userspace perspective if I understand it correctly.