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

[Xen-devel] Re: VT-d scalability issue

To: "Zhai, Edwin" <edwin.zhai@xxxxxxxxx>
Subject: [Xen-devel] Re: VT-d scalability issue
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 09 Sep 2008 11:22:15 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Tue, 09 Sep 2008 03:22:11 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20080909090427.GA6704@xxxxxxxxxxxxxxxxxxxxxx>
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: AckSZe30LGUdZ35ZEd2RyQAWy6hiGQ==
Thread-topic: VT-d scalability issue
User-agent: Microsoft-Entourage/11.4.0.080122


On 9/9/08 10:04, "Zhai, Edwin" <edwin.zhai@xxxxxxxxx> wrote:

> following code in vmx_do_resume try to invalidate orig processor's cache when
> 14 migration if this domain has pass-through device and no support for wbinvd
> vmexit.          
> 16 if ( has_arch_pdevs(v->domain) && !cpu_has_wbinvd_exiting )
> {
>     int cpu = v->arch.hvm_vmx.active_cpu;
>     if ( cpu != -1 )
>         on_selected_cpus(cpumask_of_cpu(cpu), wbinvd_ipi, NULL, 1,
> 
> }
> 
> So we want to pin vcpu to free processor for domains with pass-through device
> in
> creation process, just like what we did for NUMA system.

(a) pinning support already exists.Maybe list this as 'best practice' but I
don't see any need for xend changes, for example.
(b) presumably your upcoming (and existing current?) processors support
wbinvd exiting anyway?

 -- Keir



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