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

[Xen-devel] Re: [PATCH][RFC]Provide fast write emulation path to release

To: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Subject: [Xen-devel] Re: [PATCH][RFC]Provide fast write emulation path to release shadow lock
From: Tim Deegan <Tim.Deegan@xxxxxxxxxx>
Date: Tue, 22 Jan 2008 09:26:08 +0000
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Tue, 22 Jan 2008 01:29:38 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <D470B4E54465E3469E2ABBC5AFAC390F024D8E8C@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
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: <D470B4E54465E3469E2ABBC5AFAC390F024D8E8C@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.13 (2006-08-11)
At 10:20 +0800 on 22 Jan (1200997253), Tian, Kevin wrote:
> We also did series of tests on 32/32pae/32e: (host is 32e)
>                    32       32pae       32e
> ----Linux----
> kernel build   +1%    +0.86%    +1.9%
> Specjbb        +0.9% +1.61%    +0.32%
> 
> ----XP----
> Sysbench     N/A     -0.05%     -0.32%(*)
> 
> * Sysbench score is not very stable on 32e guest, with up
> to 6% variation observed in 5 rounds running. 32pae is
> stable. 32 XP image was unfortunately corrupted at test 
> cycle, so not test yet. Don't want to hold here from getting
> early comments. :-)
> 
> I thought the performance gain should be straightforward
> with this patch, and thus would like to know comment
> like:
>       - Is it a right direction?

Looks good to me! 

>       - Is there anything wrong or missed in patch?

Nothing fundamental that I can see by reading through it.  One thing I'd
change is to avoid introducing "vfn": a virtual address >> PAGE_SIZE is
just a "page number".

>       - Any more benchmarks should we test?

Anything and everything. :)  Specially multi-vcpu mixed operations
(e.g. kernel compile + ltp + network traffic) while doing live migrate.
Even when they look as clean as this one, changes in the shadow fault
handler tend to chase out implicit/forgotten assumptions.

Cheers,

Tim.

-- 
Tim Deegan <Tim.Deegan@xxxxxxxxxx>
Principal Software Engineer, Citrix Systems (R&D) Ltd.
[Company #02300071, SL9 0DZ, UK.]

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