Re: vmscan.c heuristic adjustment for smaller systems

[Marc Singer <elf@buici.com>]

On Sat, Apr 17, 2004 at 02:33:33PM -0700, William Lee Irwin III wrote:
> On Sat, Apr 17, 2004 at 12:38:55PM -0700, William Lee Irwin III wrote:
> >> Marc Singer reported an issue where an embedded ARM system performed
> >> poorly due to page replacement potentially prematurely replacing
> >> mapped memory where there was very little mapped pagecache in use to
> >> begin with.
> >> Marc Singer has results where this is an improvement, and hopefully can
> >> clarify as-needed. Help determining whether this policy change is an
> >> improvement for a broader variety of systems would be appreciated.
> 
> On Sat, Apr 17, 2004 at 02:29:58PM -0700, Marc Singer wrote:
> > I have some numbers to clarify the 'improvement'.
> > Setup:
> >   ARM922 CPU, 200MHz, 32MiB RAM
> >   NFS mounted rootfs, tcp, hard, v3, 4K blocks
> >   Test application copies 41MiB file and prints the elapsed time
> > The two scenarios differ only in the setting of /proc/sys/vm/swappiness.
> 
> This doesn't match your first response. Anyway, this one is gets
> scrapped. I guess if swappiness solves it, then so much the better.

Huh?  Where do you see a discrepency?  I don't think I claimed that
the test program performance changed.  The noticeable difference is in
interactivity once the page cache fills.  IMHO, 30 seconds to do a
file listing on /proc is extreme.