Re: Re: [Linux PATCH] Make hugepages work in current git tree

[Dave McCracken <dcm@mccr.org>]

On Thursday 29 April 2010, Jeremy Fitzhardinge wrote:
> On 04/29/2010 02:43 PM, Dave McCracken wrote:
> > On Thursday 29 April 2010, Jeremy Fitzhardinge wrote:
> >> Looks reasonable.  I rewrote the commit comment:
> >>
> >> Subject: [PATCH] x86/hugetlb: use set_pmd for huge pte operations
> >>
> >> On x86, a huge pte is logically a pte, but structurally a pmd.  Among
> >> other issues, pmds and ptes overload some flags for multiple uses (PAT
> >> vs PSE), so it is necessary to know which structural level a pagetable
> >> entry is in order interpret it properly.
> >>
> >> When huge pages are used within a paravirtualized system, it is
> >> therefore appropriate to use the pmd set of function to operate on them,
> >> so that the hypervisor can correctly validate the update.
> >>
> >> Signed-off-by: Dave McCracken <dave.mccracken@oracle.com>
> >> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> >>
> >> Does this look correct?
> >
> > Yes, that's an excellent summary of the issue.  Thank you.
> 
> Have you tested this patch on native as well as under Xen?

Yes, it works just fine, though see my separate post about building the current 
git tree without Xen.  I'd forgotten I had to patch it to make it build.

Dave McCracken