> -----Original Message-----
> From: Paul Mackerras [mailto:pau...@samba.org]
> Sent: Thursday, October 10, 2013 4:06 PM
> To: Wood Scott-B07421
> Cc: Bhushan Bharat-R65777; Wood Scott-B07421; ag...@suse.de; Yoder Stuart-
> B08248; k...@vger.kernel.org; kvm-ppc@vger.kernel.org
> Subject: Re: [PATCH 3/4] kvm: powerpc: define a linux pte lookup function
> 
> On Wed, Oct 09, 2013 at 12:47:31PM -0500, Scott Wood wrote:
> > On Wed, 2013-10-09 at 03:48 -0500, Bhushan Bharat-R65777 wrote:
> > >
> > > What lookup_linux_pte_and_update() does:-
> > >  - find_linux_pte_or_hugepte()
> > >  - does size and some other trivial checks
> > >  - Then atomically update the pte:-
> > >    => while()
> > >    => wait till _PAGE_BUSY is clear
> > >    => atomically update the pte
> > >    => if not updated then go back to while() above else break
> > >
> > >
> > > While what lookup_linux_pte() does:-
> > >  - find_linux_pte_or_hugepte()
> > >  - does size and some other trivial checks
> > >  - wait till _PAGE_BUSY is clear
> > >  - return pte
> > >
> > > I am finding it difficult to call lookup_linux_pte() from
> lookup_linux_pte_and_update().
> >
> > You could factor out a common lookup_linux_ptep().
> 
> I don't really think it's enough code to be worth wringing out the last drop 
> of
> duplication.  However, if he removed the checks for _PAGE_BUSY and 
> _PAGE_PRESENT
> as I suggested in another mail, and made it return the pte pointer rather than
> the value, it would then essentially be a lookup_linux_ptep() as you suggest.

Do we want to have lookup_linux_pte() or  lookup_linux_ptep() or both where 
lookup_linux_pte() and lookup_linux_pte_and_update() calls lookup_linux_ptep() ?

-Bharat

> 
> Paul.


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