From mboxrd@z Thu Jan  1 00:00:00 1970
From: Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: Re: [patch 14/21] Xen-paravirt: Add XEN config
	options and disable unsupported config options.
Date: Sat, 17 Feb 2007 15:04:35 +1100
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To: Zachary Amsden <zach@vmware.com>
Cc: xen-devel@lists.xensource.com, virtualization@lists.osdl.org, Steven Hand <steven.hand@cl.cam.ac.uk>, linux-kernel@vger.kernel.org, Chris Wright <chrisw@sous-sol.org>, Ian Pratt <ian.pratt@xensource.com>, Andrew Morton <akpm@linux-foundation.org>, Keir Fraser <keir@xensource.com>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@muc.de>
List-Id: virtualization@lists.linuxfoundation.org

On Fri, 2007-02-16 at 02:19 -0800, Zachary Amsden wrote:
> Doesn't stop_machine_run already take care of getting you out of all 
> kernel threads?  So you can only be sleeping, not preempted, in which 
> case, this might not be an issue?

No, stop_machine only protects against preempt-disabled regions.

I thought about making that particularly hammer bigger, but noone had
needed it yet.  It would simply require a runtime way of disabling
further preemption and flushing preempted threads (AFAICT there can be
no deadlock issues with this).

Rusty.