From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [Bug #13116] Can't boot with nosmp
Date: Tue, 09 Jun 2009 21:42:55 +0300
Message-ID: <4A2EAD2F.5010505@redhat.com>
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To: Stephen Hemminger <shemminger-ZtmgI6mnKB3QT0dZR+AlfA@public.gmane.org>
Cc: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, Rusty Russell <rusty-8n+1lVoiYb80n/F98K4Iww@public.gmane.org>, "Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org>, Linux Kernel Mailing List <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Kernel Testers List <kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>

Stephen Hemminger wrote:

  

>> This only affects reboots.  But yes, the cpumask code has bugs.  Does 
>> the .config involved select MAXSMP?
>>
>>     
>
> Patch does not fix the problem. Not sure if it is KVM only problem.
> Look like possible cpumask always equals what ACPI / SMP tables report.
> So currently looking into alloc_percpu which may not handle the possible
> but never used cpus.
>
>   

Right, it shouldn't have.

> It is x86-64 config and does not have MAXSMP set. It does have NR_CPUS set.
>   

So it's not cpumask.  Dare I suggest a bisect?

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.