Re: Odd swapping issue

From: Peter Zijlstra
Date: Thu Jul 24 2008 - 02:39:32 EST


On Thu, 2008-07-24 at 06:47 +0930, David Newall wrote:
> Peter Zijlstra wrote:
> > 16g ram on a 32bit kernel is stretching it... may I suggest running a
> > 64bit kernel?
> >
>
> Is it? Do we expect that behaviour with so much RAM?

I expect your 32bit machine to go wonky after say 8gb,.. maybe even
earlier for some workloads.

The thing is, 32bit machines have less than 1gb of kernel memory - the
more memory you have the less of that remains for system duties since
such things as the page frame array grow with the number of physical
pages present.

Also, all such things as buffer cache reside in that tiny space. At some
point the kernel itself is just going to run out of memory trying to
manage your machine.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/