Re: [PATCH] vmscan: evict use-once pages first (v2)

Rik van Riel
2009-05-03T03:25:42Z

On Sun, 3 May 2009 11:15:39 +0800
Wu Fengguang <fengguang.wu@intel.com> wrote:

> Commit 7e9cd484204f(vmscan: fix pagecache reclaim referenced bit
> check) tries to address scalability problem when every page get
> mapped and referenced, so that logic(which lowed the priority of
> mapped pages) could be enabled only on conditions like (priority <
> DEF_PRIORITY).
>
> Or preferably we can explicitly protect the mapped executables,
> as illustrated by this patch (a quick prototype).

Over time, given enough streaming IO and idle applications,
executables will still be evicted with just this patch.

However, a combination of your patch and mine might do the
trick. I suspect that executables are never a very big
part of memory, except on small memory systems, so protecting
just the mapped executables should not be a scalability
problem.

My patch in combination with your patch should make sure
that if something gets evicted from the active list, it's
not executables - meanwhile, lots of the time streaming
IO will completely leave the active file list alone.

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