WARNING - OLD ARCHIVES

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/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] Re: [Xen-users] Xen 4 - Page Sharing HowTo?

To: Nick Couchman <Nick.Couchman@xxxxxxxxx>, Andrew Lyon <andrew.lyon@xxxxxxxxx>, "pasik@xxxxxx" <pasik@xxxxxx>
Subject: Re: [Xen-devel] Re: [Xen-users] Xen 4 - Page Sharing HowTo?
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Sat, 10 Apr 2010 07:27:28 +0100
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, XEN Mailing List <xen-users@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Fri, 09 Apr 2010 23:28:44 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4BBF3D8B020000990004E3F7@xxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcrYJZv1+xjSk2CUTdq6DWNWYGZpTQAUUhA1
Thread-topic: [Xen-devel] Re: [Xen-users] Xen 4 - Page Sharing HowTo?
User-agent: Microsoft-Entourage/12.23.0.091001
On 09/04/2010 21:45, "Nick Couchman" <Nick.Couchman@xxxxxxxxx> wrote:

>> Sharing opportunities should result in memory being freed back to Xen. So
>> 'xm info', or whatever else you use for monitoring Xen's free memory, should
>> work.
>> 
>>  -- Keir
> 
> Hmmm...two XP HVM domUs running, and a total of 7 M freed to Xen.  Kind of
> hard to tell if memory sharing is working, or if this is normal rounding
> behavior...

The two images have to be using a common disc image (or a delta of a common
disc image) exported by a memshr-aware block-device backend: blktap1 or
blktap2. In fact, would have to be the former, since blktap2 has memshr
support disabled as it was crashing. The sharing opportunities aren't
discovered by page scanning, as in some other schemes.

 -- Keir



_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users