Additionally, a (IMO valid) maxim of sysadmins has been "a properly
configured server doesn't swap". There should be no reason why this
maxim becomes invalid over time. When Linux starts to swap out apps the
sysadmin knows will be useful in an hour, or six hours, or a day just
because it needs a bit more file cache, I get worried.
There IMO should be some way to balance the amount of anon-vma's such
that the sysadmin can say "stop taking 70% of my box's memory for
disposable cache, use it instead for apps you would otherwise swap out,
you memory-hungry kernel you."