Re: [PATCH 03/35] xen: document Xen is using an unused bit for the pagetables

Konrad Rzeszutek Wilk
2012-05-29T15:18:30Z

On Sat, May 26, 2012 at 05:59:12PM +0200, Andrea Arcangeli wrote:
> Hi Konrad,
>
> On Fri, May 25, 2012 at 04:26:56PM -0400, Konrad Rzeszutek Wilk wrote:
> > On Fri, May 25, 2012 at 07:02:07PM +0200, Andrea Arcangeli wrote:
> > > Xen has taken over the last reserved bit available for the pagetables
> > > which is set through ioremap, this documents it and makes the code
> > > more readable.
> >
> > Andrea, my previous respone had a question about this - was wondering
> > if you had a chance to look at that in your busy schedule and provide
> > some advice on how to remove the _PAGE_IOMAP altogether?
>
> I read you response but I didn't look into the P2M tree and
> xen_val_pte code yet sorry. Thanks for looking into this, if it's
> possible to remove it without downsides, it would be a nice

Yeah, I am not really thrilled about it.

> cleanup. It's not urgent though, we're not running out of reserved
> pte bits yet :).

Oh, your git comment says "the last reserved bit". Let me
look through all your patches to see how the AutoNUMA code works -
I am probably just missing something simple.