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] About resource reclamation

To: Xuxian Jiang <jiangx@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] About resource reclamation
From: Ian Pratt <Ian.Pratt@xxxxxxxxxxxx>
Date: Fri, 10 Oct 2003 18:05:15 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxxx, Ian.Pratt@xxxxxxxxxxxx
Delivery-date: Fri, 10 Oct 2003 18:06:16 +0100
Envelope-to: steven.hand@xxxxxxxxxxxx
In-reply-to: Your message of "Fri, 10 Oct 2003 11:16:44 CDT." <Pine.GSO.4.58.0310101111470.12795@xxxxxxxxxxxxxxxxxx>
List-archive: <http://sourceforge.net/mailarchive/forum.php?forum=xen-devel>
List-help: <mailto:xen-devel-request@lists.sourceforge.net?subject=help>
List-id: List for Xen developers <xen-devel.lists.sourceforge.net>
List-post: <mailto:xen-devel@lists.sourceforge.net>
List-subscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=subscribe>
List-unsubscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=unsubscribe>
Sender: xen-devel-admin@xxxxxxxxxxxxxxxxxxxxx

> I believe Xen has the similar primitives for requesting resources from
> GuestOS side. And it seems reasonable and practical to add the reverse
> functionality rescinding resource usage back from GuestOS. Such approach
> may not be possible considering UML or VMWare, but with Xen, it should be
> possible since modification on GuestOS can be made.

Absolutely -- that's one of the big wins of para-virtualization.

For example, I'm looking forward to being able to send a message
from domain 0 to another domain saying "I wish you to release 4MB
of memory as I have another domain that is prepared to pay more
for it. You have 100ms to comply, or be terminated with extreme
prejudice." ;-)


> In one situation, where several domains have been created using overbooked
> resources, would it be nice to have some resouce reclamation capability
> which requires the cooperation between Xen and supported GuestOS?

The general plan is to avoid overbooking "guaranteed" resources
to domains, but allow domains some additional resources on a best
effort proportional share basis.

For example, we've got plans to add support for a shared buffer
cache using 'unused' memory, along with a 'swap cache' to speed
up swapping.

Volunteers welcome ;-)

Best,
Ian






-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
SourceForge.net hosts over 70,000 Open Source Projects.
See the people who have HELPED US provide better services:
Click here: http://sourceforge.net/supporters.php
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel