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Date: Tue, 6 Jun 2006 17:24:10 -0700
From: Andrew Morton <akpm@osdl.org>
To: Nigel Cunningham <ncunningham@linuxmail.org>
Cc: jeremy@goop.org, dzickus@redhat.com, ak@suse.de, shaohua.li@intel.com,
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Subject: Re: [2.6.17-rc5-mm2] crash when doing second suspend: BUG in
 arch/i386/kernel/nmi.c:174
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On Wed, 7 Jun 2006 10:13:49 +1000
Nigel Cunningham <ncunningham@linuxmail.org> wrote:

> > the new CPU to get the same state as the old one just because it ends up
> > with the same logical CPU number?  Perhaps, but what if it doesn't even
> > have the same capabilities?  (Do we support heterogeneous CPUs anyway?)
> 
> Indeed. I'm also not sure that there's necessarily a guarantee that cpus will 
> be hotplugged in the same order. Perhaps those with more knowledge can 
> clarify there.

It all depends on what we mean by "per-cpu state".  If we were to remember
that "CPU 7 needs 0x1234 in register 44" then that would be wrong.  But
remembering some high-level functional thing like "CPU 7 needs to run the
NMI watchdog" is fine.  The CPU bringup code can work out whether that is
possible, and how to do it.