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] pv 2.6.31 (kernel.org) and save/migrate fails, domU BUG

To: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Subject: Re: [Xen-devel] pv 2.6.31 (kernel.org) and save/migrate fails, domU BUG
From: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
Date: Wed, 25 Nov 2009 20:03:05 +0000
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>, Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>, "Xen-Devel \(E-mail\)" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Gleixner <tglx@xxxxxxxxxxxxx>, Thomas
Delivery-date: Wed, 25 Nov 2009 12:03:31 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4B0D8554.3010103@xxxxxxxx>
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>
Organization: Citrix Systems, Inc.
References: <20091108154153.GM1434@xxxxxxxxxxx> <693ea516-aa5b-4f82-ad48-1bd51cfa3480@default> <20091108172747.GR1434@xxxxxxxxxxx> <20091110100806.GE16033@xxxxxxxxxxx> <4AFC9BFF.9030707@xxxxxxxx> <1259072824.7590.389.camel@xxxxxxxxxxxxxxxxxxxxxx> <1259158328.7590.539.camel@xxxxxxxxxxxxxxxxxxxxxx> <4B0D8554.3010103@xxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Wed, 2009-11-25 at 19:28 +0000, Jeremy Fitzhardinge wrote: 
> On 11/25/09 06:12, Ian Campbell wrote:
> > tick_resume() is never called on secondary processors. Presumably this
> > is because they are offlined for suspend on native and so this is
> > normally taken care of in the CPU onlining path. Under Xen we keep all
> > CPUs online over a suspend.
> >
> > This patch papers over the issue for me but I will investigate a more
> > generic, less hacky, way of doing to the same.
> >
> > tick_suspend is also only called on the boot CPU which I presume should
> > be fixed too.
> >   
> 
> Yep.  I wonder how it ever worked?  There's been a fair amount of change
> in the PM code, so that could have changed things.  I don't know if
> there's a deep reason for not calling tick_resume() on all processors.
> 
> Rafael, tglx: suspend/resume under Xen doesn't need to hot unplug all
> the CPUs, so we don't; the hypervisor can manage the context
> save/restore for all CPUs.  Is there a deep reason why
> timekeeping_resume() can't call the CLOCK_EVT_NOTIFY_RESUME notifier on
> all online CPUs?

Interrupts are disabled at that point where it currently calls the
notifier, so none of the SMP function call primitives work.

> >  void xen_arch_resume(void)
> >  {
> > -   /* nothing */
> > +   smp_call_function_many(cpu_online_mask, xen_vcpu_notify_restore,
> > +                          (void *)CLOCK_EVT_NOTIFY_RESUME, 1);
> >  }
> >   
> 
> This is equivalent to smp_call_function().

Oh yeah.

Ian.


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

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