On Thu, 2010-08-26 at 18:29 +0900, Minchan Kim wrote:

As I said following mail, I said about free space problem.
Of course, compaction could move anon pages into somewhere.
What's is somewhere? At last, it's same zone.
It can prevent fragment problem but not size of free space.
So I mean it would be better to move it into another zone(ex, HIGHMEM)
rather than OOM kill. 

Real machines don't have highmem, highmem sucks!! /me runs

Does cross zone movement really matter, I though these crappy devices
were mostly used on crappy hardware with very limited memory, so pretty
much everything would be in zone_normal.. no?

But sure, if there's really a need we can look at maybe doing cross zone
movement.