Re: vmscan.c heuristic adjustment for smaller systems

Marc Singer
2004-04-18T05:38:59Z

On Sat, Apr 17, 2004 at 08:53:38PM -0700, Andrew Morton wrote:
> William Lee Irwin III <wli@holomorphy.com> wrote:
> >
> > On Sat, Apr 17, 2004 at 04:51:51PM -0700, Andrew Morton wrote:
> > > I'd assume that setting swappiness to zero simply means that you still have
> > > all of your libc in pagecache when running ls.
> > > What happens if you do the big file copy, then run `sync', then do the ls?
> > > Have you experimented with the NFS mount options? v2? UDP?
> >
> > I wonder if the ptep_test_and_clear_young() TLB flushing is related.
>
> That, or page_referenced() always returns true on this ARM implementation
> or some such silliness. Everything here points at the VM being unable to
> reclaim that clean pagecache.

How can I tell? Is it something like this: because page_referenced()
always returns true (which I haven't investigated) then the page
eviction code cannot distinguish mapped from cache pages and therefore
selects valuable, mapped pages.