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/RFC] Wrong account for cpus other than 0 on hotpl

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH/RFC] Wrong account for cpus other than 0 on hotplug
From: Glauber de Oliveira Costa <gcosta@xxxxxxxxxx>
Date: Fri, 13 Oct 2006 18:18:50 -0300
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 13 Oct 2006 14:20:20 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C155B6C1.2829%Keir.Fraser@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: <20061013175025.GA13539@xxxxxxxxxx> <C155B6C1.2829%Keir.Fraser@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.11
On Fri, Oct 13, 2006 at 09:33:53PM +0100, Keir Fraser wrote:
> On 13/10/06 6:50 pm, "Glauber de Oliveira Costa" <gcosta@xxxxxxxxxx> wrote:
> 
> 
> This patch turns off the missing ticks accounting entirely, as the
> runstate_info structure will never be updated. Are you sure this appears to
> be an x86_64-specific issue?

That's why I was almost sure it was wrong, and was expecting comments
:-)
Among all machines we have, it just seem to be happening in a few of
them. Besides being x86_64, they're 8-way, which can be another sort of
problem.

I just found that the offending code is in the HV itself, and not in the
guest. In arch_do_vcpu_op(), we see that the information is only passed
up to the guest, if the check (current == v) holds, which seems to be
the
true source of it. (taking the check away makes it work).

I can see no reason for this check to be there. If there is one, we
could maybe make sure it holds. (maybe calling set_current(v) on HV
side?)

Your comments on this are , as usual, very welcome ;-)


-- 
Glauber de Oliveira Costa
Red Hat Inc.
"Free as in Freedom"

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

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