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] [PATCH] x86: use 'dom0_mem' to limit the number of pages

To: Ian Campbell <Ian.Campbell@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] x86: use 'dom0_mem' to limit the number of pages for dom0
From: David Vrabel <david.vrabel@xxxxxxxxxx>
Date: Tue, 16 Aug 2011 14:11:47 +0100
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Delivery-date: Tue, 16 Aug 2011 06:12:37 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <1313499116.5010.104.camel@xxxxxxxxxxxxxxxxxxxxxx>
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: <1ec6c392d40f37032b0c.1313431713@qabil> <20110816003158.GA26540@xxxxxxxxxxxx> <4E4A62B9.4030302@xxxxxxxxxx> <1313499116.5010.104.camel@xxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.18) Gecko/20110617 Thunderbird/3.1.11
On 16/08/11 13:51, Ian Campbell wrote:
> 
> The key difference is that classic-Xen kernels called both
> XENMEM_memory_map and XENMEM_machine_memory_map and dealt with both,
> whereas pvops (dom0) calls XENMEM_machine_memory_map and tries to figure
> out how much of the E820_RAM therein it can actually use based on
> nr_pages and such. You've used XENMEM_maximum_reservation in your
> followup series which I think is a suitable surrogate for calling
> XENMEM_memory_map (although I didn't check).

XENMEM_memory_map for dom0 doesn't work as nothing populates the map.

Classic-Xen kernels appear to invent a memory map based only on nr_pages
and it's non-obvious where it gets any other limit from (I didn't look
that hard though).

I did originally make XENMEM_memory_map work for dom0 but using
XENMEM_maximum_reservation looked more relevant.

David

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