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] irq_guest_eoi_timer interaction with MSI

To: Jan Beulich <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] irq_guest_eoi_timer interaction with MSI
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 13 Nov 2008 16:22:54 +0000
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 13 Nov 2008 08:23:19 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C542048A.290E1%keir.fraser@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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AclFq+KWINmAHrGfEd2N7wAX8io7RQAADISJ
Thread-topic: [Xen-devel] irq_guest_eoi_timer interaction with MSI
User-agent: Microsoft-Entourage/11.4.0.080122
On 13/11/08 16:21, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:

>> But then there'd be a hypercall for each MSI instance, most of the time
>> without any real need. With a high interrupt rate I'm afraid this does
>> matter.
> 
> I don't understand what you mean. There is a one-to-one-one relationship
> between MSIs, PIRQs, and event channels.

Also I'll add we currently do a hypercall for every level-triggered IO-APIC
IRQ, which was really all we supported until recently. Seemed to work well
enough performance-wise in that case.

 -- Keir



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