From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@citrix.com>
Subject: Re: XEN same page merging.
Date: Wed, 20 May 2015 11:32:04 +0100
Message-ID: <555C62A4.4010601@citrix.com>
References: <1432111281727.48589@mail.aub.edu>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta3.messagelabs.com ([195.245.230.39])
	by lists.xen.org with esmtp (Exim 4.72)
	(envelope-from <julien.grall@citrix.com>) id 1Yv1Im-0001CT-Ir
	for xen-devel@lists.xenproject.org; Wed, 20 May 2015 10:32:40 +0000
In-Reply-To: <1432111281727.48589@mail.aub.edu>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: "Mazen Ezzeddine (Student)" <emm09@mail.aub.edu>, "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
List-Id: xen-devel@lists.xenproject.org

On 20/05/15 09:41, Mazen Ezzeddine (Student) wrote:
> Dear all,

Hello,

> Could you please advise me whether XEN has a mechanism to merge/map same
> memory pages of different VMs into a single physical page in the
> available physical address space. If yes, is there a compilation flag
> to disable such feature?

Xen doesn't merge/map automatically the same physical memory page in
different VMs.

Although, it may be possible for a guest to map a page from another
domain in order to copy data.

Regards,

-- 
Julien Grall