I think the current memory_pressure calculation is broken - at least
memory_pressure does not contain the number of pages necessary in the
inactive_clean_list to handle 1 second of allocations.

* if reclaim_page() finds a page that is Referenced, Dirty or Locked
then it must increase memory_pressure.
* I don't understand the purpose of the second ++ in alloc_pages().

What about the attached patch [vs. 2.4.5]? It's just an idea, untested.

If the behaviour is worse then we must figure out what memory_pressure
actually is under the various workloads. AFAICS it has nothing to do
with the number of memory allocations per second.

Please cc me, I'm not subscribed to linux-mm.

--
	Manfred