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] vram_dirty vs. shadow paging dirty tracking

To: Anthony Liguori <aliguori@xxxxxxxxxx>
Subject: Re: [Xen-devel] vram_dirty vs. shadow paging dirty tracking
From: "Zhai, Edwin" <edwin.zhai@xxxxxxxxx>
Date: Thu, 15 Mar 2007 10:59:34 +0800
Cc: Ian Pratt <m+Ian.Pratt@xxxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx, "Zhai, Edwin" <edwin.zhai@xxxxxxxxx>
Delivery-date: Wed, 14 Mar 2007 20:04:17 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <45F81C11.1020404@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>
References: <45F6FC68.3040207@xxxxxxxxxx> <20070314082210.GX12238@xxxxxxxxxxxxxxxxxxxxxx> <45F81C11.1020404@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.11
On Wed, Mar 14, 2007 at 11:00:17AM -0500, Anthony Liguori wrote:
> Zhai, Edwin wrote:
> >On Tue, Mar 13, 2007 at 02:32:56PM -0500, Anthony Liguori wrote:
> >  
> >>When thinking about multithreading the device model, it occurred to me 
> >>that it's a little odd that we're doing a memcmp to determine which 
> >>portions of the VRAM has changed.  Couldn't we just use dirty page 
> >>    
> >
> >we made this code to improve the user vnc responsiveness long before.
> >now QEMU has new vnc implementation to resolve this issue and this code 
> >introduce perf drop for guest of linux with X or windows.
> >  
> 
> Compared to what, just updating the full screen 30 times a second?  I 
> suspect that's not as bad as it sounds since SDL will be using a XShmImage.

removing the memcpy and having whole screen update each time has better 
performance.

> 
> The VNC minimization is done based on a timer however so sticking the 
> timer stuff into a thread is still useful.  Of course, we should be able 
> to quickly determine how useful this is by just changing SDL to update 
> the whole image...
> 
> Regards,
> 
> Anthony Liguori
> 
> >so i'd like to send a patch to revert it and make a proper solution in 
> >future.
> >
> >thanks,
> >
> >  

-- 
best rgds,
edwin

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