From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: pv_ops & gntdev?
Date: Wed, 25 Feb 2009 13:48:13 -0800
Message-ID: <49A5BC9D.5010801@goop.org>
References: <49A44030.2070709@redhat.com> <49A4640E.1000807@goop.org>
	<49A470DD.2000008@redhat.com> <49A517F6.30005@redhat.com>
	<49A58506.2020407@goop.org> <49A58FFF.3050604@redhat.com>
	<49A5A4BD.7080207@goop.org> <49A5B5DD.60309@redhat.com>
	<49A5B9AA.7010709@goop.org> <49A5BB7E.8030503@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xensource.com>
In-Reply-To: <49A5BB7E.8030503@redhat.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Xen Development Mailing List <xen-devel@lists.xensource.com>
List-Id: xen-devel@lists.xenproject.org

Gerd Hoffmann wrote:
> Hmm.  One more Q:  How is pinning used?  Is a process pinned all the
> time?  Or can it happen that the pages are unpinned in case it does hang
> around idle for a while?  Is there some way to prevent a process from
> being unpinned?
>   

Pinning in the sense of Xen pagetables; a pagetable is pinned for the 
whole time the process exists - it gets pinned at fork/exec time, and 
unpin on exit.  (It has no effect on the residency of the usermode 
pages, though granted pages mapped into usermode would not be swappable 
at all.)

> I somehow feel like checking out mmu notifiers first ...
>   
Why's that?  What would you use them for?

    J