This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


RE: [Xen-devel] [PATCH] Do not set page's count_info directly

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>, Gianluca Guida <glguida@xxxxxxxxx>, Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH] Do not set page's count_info directly
From: "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>
Date: Thu, 5 Mar 2009 22:34:45 +0800
Accept-language: en-US
Acceptlanguage: en-US
Cc: Gianluca, Guida <Gianluca.Guida@xxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 05 Mar 2009 06:38:18 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C5D58212.43AC%keir.fraser@xxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <f8877f640903050445s5d277287yf01fc8aa77b0e30b@xxxxxxxxxxxxxx> <C5D58212.43AC%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcmdkFA66cwCWtGQT6aFUeqlRi5oGQABNBq3AAKM6+A=
Thread-topic: [Xen-devel] [PATCH] Do not set page's count_info directly
Keir Fraser <mailto:keir.fraser@xxxxxxxxxxxxx> wrote:
> On 05/03/2009 12:45, "Gianluca Guida" <glguida@xxxxxxxxx> wrote:
>> On Thu, Mar 5, 2009 at 1:38 PM, Tim Deegan
> <Tim.Deegan@xxxxxxxxxx> wrote:
>>> The check doesn't tell you it's a shadow page -- it just tells you it's
>>> *not* allocated in another way.  Checking with the mask is OK here,
>>> perhaps with a comment change.
>> Yes, but this is what the code (in the shadow code) intends to check.
>> My complete plan is to have this macro and restore the idea of having
>> a flag for shadow pages because, as for now, the fact that we can't
>> distinguish clearly a shadow page should be considered a sort of bug,
>> given the code assumptions. Or at least a good basis for future bugs.
> I'm happy for shadow code to have another bit in count_info
> for its own use.
> I don't think it's good to have other code (e.g., generic page offlining
> code) peeking at it, is all. The particular case for a new
> flag described
> above sounds fine.

The new code is not using that flag anymore, it is use the 
page_get_owner_and_reference() to get the owner.

Yunhong Jiang

> -- Keir
Xen-devel mailing list