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] abstract request_evtchn

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] abstract request_evtchn
From: Matt Chapman <matthewc@xxxxxx>
Date: Tue, 2 Aug 2005 14:26:18 -0600
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Tue, 02 Aug 2005 20:24:43 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <29648f61681c07781d8e8e1e663c151f@xxxxxxxxxxxx>
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: <20050801223210.GA4532@xxxxxxxxxxxxxxx> <29648f61681c07781d8e8e1e663c151f@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.1i
On Tue, Aug 02, 2005 at 12:43:43PM +0100, Keir Fraser wrote:
> 
> On 1 Aug 2005, at 23:32, Matt Chapman wrote:
> 
> >This patch provides request_evtchn and free_evtchn, intended
> >to be used instead of bind_evtchn_to_irq/request_irq and
> >free_irq/unbind_evtchn_from_irq.  This allows architectures
> >to implement event channels as they see fit, not necessarily
> >using Linux IRQs.
> 
> Why would you not hook into the IRQ subsystem? This doesn't seem like a 
> useful patch to me.

I'm trying to keep all the Xen drivers and related infrastructure in
modules - IMHO domains that aren't paravirtualised should be able to
use the optimised drivers too, plus it makes development easier.

irq_desc isn't exported from the Linux kernel on most architectures,
so I'm not sure how one would "hook into" the IRQ subsystem in that
way from a module.  Also, this limits the number of event channels to
NR_IRQS (minus the ones that are used in other ways).  Instead I have
the event channel subsystem register for a single IRQ and then
demultiplex internally (in the way that is already done by
evtchn_do_upcall).

Matt


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

<Prev in Thread] Current Thread [Next in Thread>