Comment 549 for bug 620074

Hm, I then have another wild suggestion.

It is in fact a very rare event that a process needs to hang in memory but wake up once in a blue moon, so that it can be harmlessly paged out and not bring the system to a halt. From my desktop experience I can only remember LibreOffice sitting on my long-running machine and be actually used once in two weeks or so.

If the problem is really so grave that an often-running process (like Xorg!) is selected by the kernel to be paged out, why not work this around by disabling evicting processes' pages altogether? I think it must be somewhat easier than designing an over-engineered strategy for choosing what pages to throw away, test it over a couple years, find bugs in the very design, throw it away, design another one and so on.

I would love to see a flag which I could set per control group. If the flag is set, pages owned by processes in that cgroup are never swapped out. Combined with pessimistic overcommit policy, it could help at least a bit.

Or at least worth a try.