Subject: Re: [PATCH 5/7] powerpc/mm: 64-bit: don't handle non-standard page sizes

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 19 May 2011 07:54:05 +1000

On Wed, 2011-05-18 at 16:50 -0500, Scott Wood wrote:
> On Thu, 19 May 2011 07:36:04 +1000
> Benjamin Herrenschmidt <[email-masked]> wrote:
> 
> > On Wed, 2011-05-18 at 16:05 -0500, Scott Wood wrote:
> > > I don't see where any non-standard page size will be set in the
> > > kernel page tables, so don't waste time checking for it.  It wouldn't
> > > work with TLB0 on an FSL MMU anyway, so if there's something I missed
> > > (or which is out-of-tree), it's relying on implementation-specific
> > > behavior.  If there's an out-of-tree need for occasional 4K mappings
> > > with CONFIG_PPC_64K_PAGES, perhaps this check could only be done when
> > > that is defined.
> > > 
> > > Signed-off-by: Scott Wood <[email-masked]>
> > > ---
> > 
> > Do you use that in the hugetlbfs code ? Can you publish that code ? It's
> > long overdue...
> 
> hugetlbfs entries don't get loaded by this code.  It branches to a slow
> path based on seeing a positive value in a pgd/pud/pmd entry.

BTW. The long overdue was aimed at David to get A2 hugetlbfs out :-)

Cheers,
Ben.