Re: swapping and the value of /proc/sys/vm/swappiness

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

On Tue, Sep 14, 2004 at 11:31:53AM -0700, Florin Andrei wrote:
> On Mon, 2004-09-06 at 16:27, Andrew Morton wrote:
> > Con Kolivas <kernel@kolivas.org> wrote:
> 
> > >  The change was not deliberate but there have been some other people report 
> > >  significant changes in the swappiness behaviour as well (see archives). It 
> > >  has usually been of the increased swapping variety lately. It has been 
> > >  annoying enough to the bleeding edge desktop users for a swag of out-of-tree 
> > >  hacks to start appearing (like mine).
> > 
> > All of which is largely wasted effort.
> 
> >From a highly-theoretical, ivory-tower perspective, maybe; i am not the
> one to pass judgement.
> >From a realistic, "fix it 'cause it's performing worse than MSDOS
> without a disk cache" perspective, definitely not true.
>
> I've found a situation where the vanilla kernel has a behaviour that
> makes no sense:
> 
> http://marc.theaimsgroup.com/?l=linux-kernel&m=109237941331221&w=2
> http://marc.theaimsgroup.com/?l=linux-kernel&m=109237959719868&w=2
> http://marc.theaimsgroup.com/?l=linux-kernel&m=109238126314192&w=2
> 
> A patch by Con Kolivas fixed it:
> 
> http://marc.theaimsgroup.com/?l=linux-kernel&m=109410526607990&w=2
> 
> I cannot offer more details, i have no time for experiments, i just need
> a system that works. The vanilla kernel does not.

Have you tried to decrease the value of /proc/sys/vm/swappiness 
to say 30 and see what you get?

Andrew's point is that we should identify the problem - Con's patch
rewrites swapping policy.