> der Mouse is right except for certain ocasions/enviroments where you
> don't know when you'll need free memory pages.

Even that doesn't matter, provided you know you can take them away
whenever you want.  Push their contents to disk, make sure nobody's got
them mapped, and you don't have to "start VM/cache synchronization" to
reclaim one; you just need to note that you no longer have an in-core
copy of that page lying around, and clear it.  (I do know how bad it
can get under the wrong circumstances; some of the work I did involved
cases where the OS _did_ run out of free pages.  We ran into some
rather unpleasant livelocks under certain stress tests.)

Now, I don't know whether that is what uvm actually does in the case at
hand.  But it certainly could in theory.

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