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: remove use of per-domain lock from page tab

To: Jan Beulich <jbeulich@xxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] x86: remove use of per-domain lock from page table entry handling
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 22 Apr 2008 14:30:20 +0100
Delivery-date: Tue, 22 Apr 2008 06:31:04 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <480DFDD8.76E4.0078.0@xxxxxxxxxx>
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: AcikfQKBQVzMmRBwEd2NMQAX8io7RQ==
Thread-topic: [Xen-devel] [PATCH] x86: remove use of per-domain lock from page table entry handling
User-agent: Microsoft-Entourage/11.4.0.080122
On 22/4/08 14:01, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:

> This is only a first step, the use of the domain lock in do_mmuext_op()
> and do_set_gdt() still need looking at, as do the assertions of the
> lock being held in create_grant_{pte,va}_mapping().
> 
> This change results in a 5% performance improvement for kernel builds
> on dual-socket quad-core systems (which is what I used for reference
> for both 32- and 64-bit). Along with that, the amount of time reported
> as spent in the kernel gets reduced by almost 25% (the fraction of time
> spent in the kernel is generally reported significantly higher under
> Xen than with a native kernel).

I'm pretty sure we don't need per-page locks.

 -- Keir



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