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Re: [Xen-devel] How to generate a HW NMI

On Fri, Oct 01, 2010 at 02:33:20PM -0500, Roger Cruz wrote:
> Great ideas Konrad.  I have ordered these parts.  It will probably take
> a few days before they get here.
> The goal of using the HW NMI is to rule out any incorrect SW settings of
> the Performance Monitoring counters used in Xen to triggered the NMI.

> Someone else mentioned that another possibility as to why an NMI may not
> be triggered is that the system is stuck handling an SMI interrupt.  I
> haven't studied Xen code with respect to SMIs yet, but I assume that Xen
> doesn't do much in that area right?  I was under the impression that the
> BIOS usually set this up and the OSs could not even modify the handlers
> as they were in protected RAM.

Ugh. That is true - we have no notion of when the SMIs run. Not that
the SMIs are actually working 100% all the time.

Another thought, and this might be a complete shoot in the dark.
Look in the upstream (2.6.36-rc6) blacklist.c file. There is an entry
for that specific ThinkPad which activates the ACPI _OSI, maybe that
needs to be done?

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