From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave McCracken Subject: Re: Re: [Linux PATCH] Make hugepages work in current git tree Date: Thu, 29 Apr 2010 16:43:16 -0500 Message-ID: <201004291643.16613.dcm@mccr.org> References: <20100428140825.17161.27594.sendpatchset@magnum.int.mccr.org> <4BD9DE3D.9070204@goop.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4BD9DE3D.9070204@goop.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: Jeremy Fitzhardinge , Jan Beulich List-Id: xen-devel@lists.xenproject.org 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 > Signed-off-by: Jeremy Fitzhardinge > > Does this look correct? Yes, that's an excellent summary of the issue. Thank you. Dave McCracken