Xen 
 
Home About Xen.org Xen Xen Summit Wiki Mailing List Bug Tracker Xen Downloads
 
   
 

xen-devel

Re: [Xen-devel] page table walk in xen_{create, destroy}_contiguous_regi

To: "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] page table walk in xen_{create, destroy}_contiguous_region
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Thu, 29 Jun 2006 15:46:18 +0200
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 29 Jun 2006 06:46:26 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <fa1766bdb58a62435375e894772defa7@xxxxxxxxxxxx>
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>
References: <44A002EC.76E4.0078.0@xxxxxxxxxx> <fa1766bdb58a62435375e894772defa7@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
>> Is there a particular reason why these functions need to walk the page 
>> table rather than doing a much cheaper p2m
>> translation? vstart is assumed to be in the direct mapping area anyway 
>> (otherwise the uses of __pa() in the same
>> functions wouldn't be valid).
>>
>> Thanks, Jan
>
>Looks like the walks are not really needed.

Subject: Replace page table walks by simple address calculation
Signed-off-by: jbeulich@xxxxxxxxxx 

Makes the code both smaller and faster.


Attachment: xenlinux-ccr-dcr-no-pgtable-walk.patch
Description: Text document

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>