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-ia64-devel

Re: [Xen-devel] [PATCH] fix memory exchange hypercall.

To: Keir Fraser <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] fix memory exchange hypercall.
From: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Date: Thu, 15 Mar 2007 22:38:19 +0900
Cc: Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx, xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 15 Mar 2007 06:37:33 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C21EEB38.B8AD%keir@xxxxxxxxxxxxx>
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: <20070315114201.GC1819%yamahata@xxxxxxxxxxxxx> <C21EEB38.B8AD%keir@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.2.1i
On Thu, Mar 15, 2007 at 12:23:20PM +0000, Keir Fraser wrote:
> Whichever, I think we should sort it out one way or the other and change
> ia64 and/or x86 now. Or it'll never happen!

I see. To be honest I expected this kind of response.
I'll give it a try again, but it may take a while.

Could you explain about PGC_allocated and balloon?
What's the rationale when to clear/set PGC_allocate bit?

My understanding is as follows.
- PGC_allocated means +1 page reference count.
- It is neccessary for x86 paravirtualized domain to keep
  page from freeing.
- It doesn't make sense for x86 hvm domain so that it is only cleared
  by relinquish_memory().
- If the p2m entry is cleared which isn't followed by
  clearing PGC_allocaed and put_page() without any recording,
  there is no easy way to free the page until domain destruction.

thnaks,
-- 
yamahata

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