Re: [patch 1] Xen core patch : ptep_establish_new

[Paul Mackerras <paulus@samba.org>]

Christoph Hellwig writes:

> On Wed, Nov 17, 2004 at 11:46:50PM +0000, Ian Pratt wrote:
> > 
> > This patch adds 'ptep_establish_new', in keeping with the
> > existing 'ptep_establish', but for use where a mapping is being
> > established where there was previously none present. This
> > function is useful (rather than just using set_pte) because
> > having the virtual address available enables a very important
> > optimisation for arch-xen. We introduce
> > HAVE_ARCH_PTEP_ESTABLISH_NEW and define a generic implementation
> > in asm-generic/pgtable.h, following the pattern of the existing
> > ptep_establish.
> 
> What would be the problem of always passing the virtual address to
> ptep_establish?  We already have a rather twisted maze of pte manipulation
> macros.

Dave Miller had a patch that passes the mm and virtual address to
set_pte.  That helps on sparc64 and ppc/ppc64, and it sounds like it
would help here too.

Paul.