Re: vmscan.c heuristic adjustment for smaller systems

From: Nick Piggin
Date: Sat Apr 17 2004 - 22:39:09 EST

Marc Singer wrote:
On Sat, Apr 17, 2004 at 04:51:51PM -0700, Andrew Morton wrote:

Marc Singer <elf@xxxxxxxxx> wrote:

On Sat, Apr 17, 2004 at 04:21:25PM -0700, Andrew Morton wrote:

How on earth can it take half a minute to list /proc?

I've watched the vmscan code at work. The memory pressure is so high
that it reclaims mapped pages zealously. The program's code pages are
being evicted frequently.

Which tends to imply that the VM is not reclaiming any of that nfs-backed

I don't think that's the whole story. They question is why.

swappiness is pretty arbitrary and unfortunately it means
different things to machines with different sized memory.

Also, once you *have* gone past the reclaim_mapped threshold,
mapped pages aren't really given any preference above
unmapped pages.

I have a small patchset which splits the active list roughly
into mapped and unmapped pages. It might hopefully solve your
problem. Would you give it a try? It is pretty stable here.

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