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-ia64-devel] lsapic deliver external IRQ

To: "Magenheimer, Dan \(HP Labs Fort Collins\)" <dan.magenheimer@xxxxxx>, <xen-ia64-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-ia64-devel] lsapic deliver external IRQ
From: "Dong, Eddie" <eddie.dong@xxxxxxxxx>
Date: Mon, 2 May 2005 08:43:24 +0800
Cc: ipf-xen <ipf-xen@xxxxxxxxx>
Delivery-date: Mon, 02 May 2005 00:43:17 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-ia64-devel-request@lists.xensource.com?subject=help>
List-id: DIscussion of the ia64 port of Xen <xen-ia64-devel.lists.xensource.com>
List-post: <mailto:xen-ia64-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcVNWmsE03s0PVd0RSGIR7DeS8HlZwApJXCgAA+89RAAFgPrQAAD3ctw
Thread-topic: [Xen-ia64-devel] lsapic deliver external IRQ
Magenheimer, Dan (HP Labs Fort Collins) wrote:
> 
> I see... if you are suggesting that the call to
> check_pending_interrupts is expensive and returns "no
> interrupt" almost all the time, I fully agree.
> This call could/should be changed to just check
> the domain's pending_interruption flag.  But I seem
> to recall that I tried that and the test failed (probably
> the machine froze) so I fell back to the more conservative
> call that worked.  Perhaps it is time to try it again.
> 
> Dan
Thanks, we got same point.

BTW, set pending_interruption flag has potential issue as vpsr.i and
vtpr may change time by time. My proposal will eliminate
deliver_pending_interrupt function so that HV return to guest will not
need to check any pending IRQs. Instead when guest vIRR get changed or
vpsr.i and vtpr get changed, I inject/reflect interruption immediately
if it meets the interrupt deliver condition. (I.e change guest context
for external IRQ immediately).
I will provide this patch together in the merge if you like to see it.
Eddie

_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel

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