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] Make "xm mem-set" be lower bound ondomX-min-mem

To: "Gareth S Bestor" <bestor@xxxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH] Make "xm mem-set" be lower bound ondomX-min-mem
From: "Puthiyaparambil, Aravindh" <aravindh.puthiyaparambil@xxxxxxxxxx>
Date: Sat, 20 May 2006 17:50:31 -0400
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Sat, 20 May 2006 14:51:13 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcZ8U7gPbOc+QLf4Tyehe81fKXe/rwAA24eg
Thread-topic: [Xen-devel] [PATCH] Make "xm mem-set" be lower bound ondomX-min-mem

Yes, trying to balloon a domain to less than 2% of its initial memory allocation causes things to go haywire.






From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Gareth S Bestor
Sent: Saturday, May 20, 2006 5:28 PM
To: Keir Fraser
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] [PATCH] Make "xm mem-set" be lower bound ondomX-min-mem


>...shrinking to <2% of original allocation is a very bad idea

An absolute limit might be easier to handle - and expose to users - than a relative one, especially up-front in CIM where it exposes min/max limits on resource allocations. Or is it really <2% of whatever the original memory allocation is when things go to kabluwey... ?

BTW - at the moment we are exposing a 16MB minimum DomU memory size thru our CIM providers resource allocation defaults, although this is more a hint than anything actually enforced; the mgmt client can still pass in whatever value they like and we (CIM) will blindly pass it along to xm create ...

- Gareth

Dr. Gareth S. Bestor
IBM Linux Technology Center
M/S DES2-01
15300 SW Koll Parkway, Beaverton, OR 97006
503-578-3186, T/L 775-3186, Fax 503-578-3186

Inactive hide details for Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>

Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>

05/20/06 01:26 AM


Gareth S Bestor/Beaverton/IBM@IBMUS




Re: [Xen-devel] [PATCH] Make "xm mem-set" be lower bound on domX-min-mem


>  Unless there is an known *architectural* limit in Xen on the lower
> bound of the memory for a guest DomU, then I agree - xend
>  shouldn't impose an arbitrary one simply to act as 'hard hint' to
> prevent stupid users from doing stupid things
>  (give 'em all the rope they want I say! :-) Care-and-feeding of naive
> users is best left to tools higher up the mgmt stack (IMO).

I agree with this. I'm also not sure about putting a lower bound in the
balloon driver, but at least there we know that shrinking to <2% of
original allocation is a very bad idea with very high probability.

 -- Keir

Xen-devel mailing list
<Prev in Thread] Current Thread [Next in Thread>