Re: The performance and behaviour of the anti-fragmentation related patches

Andrew Morton
2007-03-02T04:59:04Z

On Thu, 1 Mar 2007 20:33:04 -0800 (PST) Christoph Lameter <clameter@engr.sgi.com> wrote:

> On Thu, 1 Mar 2007, Andrew Morton wrote:
>
> > Sorry, but this is crap. zones and nodes are distinct, physical concepts
> > and you're kidding yourself if you think you can somehow fudge things to make
> > one of them just go away.
> >
> > Think: ZONE_DMA32 on an Opteron machine. I don't think there is a sane way
> > in which we can fudge away the distinction between
> > bus-addresses-which-have-the-32-upper-bits-zero and
> > memory-which-is-local-to-each-socket.
>
> Of course you can. Add a virtual DMA and DMA32 zone/node and extract the
> relevant memory from the base zone/node.

You're using terms which I've never seen described anywhere.

Please, just stop here. Give us a complete design proposal which we can
understand and review.