From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: Re: [PATCH]Add a flag for shadow pages Date: Wed, 04 Mar 2009 16:45:30 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Jiang, Yunhong" , Tim Deegan , Gianluca Guida Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 04/03/2009 16:01, "Jiang, Yunhong" wrote: > Thanks for your really quick-hand implementation. I will update my another > patch accordingly tomorrow. > > So still one question to the two assertion (or to Tim??) in > sh_rm_write_access_from_sl1p()/sh_put_ref(). What's the potential error to be > protected by this checking? If page is a shadow, it's count_info will always > be 0, right? Or it is just a sanity checking? > > I need change this is because, if we mark a page offline, then the count_info > is not 0, even for shadow page. Can I just checking the count_mask here? Current shadow pages always have count_info == 0. If you add in extra flags that you want preserved in shadow pages, you'll need some modifications like in your last patch. -- Keir