Avoiding the OOM killer with mem_notify

Nokia has something similar on their Linux-based Maemo platform -- run it without swap, start
a bunch of applications, and a lot of the built-in applications would enter a
reduced-memory-usage mode -- noticeable because it takes much longer to switch to them than it
normally would.

I wonder whether the apps currently just poll the system to find out how much memory is left,
or they have their own mechanism, though.