Re: [PATCH 1/7] ia64, kdump: Mask MCA/INIT on freezing cpus

From: Robin Holt
Date: Tue Jun 23 2009 - 01:55:49 EST


On Tue, Jun 23, 2009 at 09:33:46AM +0900, Hidetoshi Seto wrote:
> Robin Holt wrote:
...
> Do you mean that the 2nd kernel should be able to handle MCA/INIT from its
> boot up? I guess the word PROM is nearly equal to PAL/SAL firmware, if so
> then I don't think there are good generic interface/procedure could be
> useful here. Do you have any concrete idea?

No concrete ideas. Just a really uneasy feeling whenever the INIT
is disabled.

On SGI's ia64 servers, when the INIT is first received, our PROM (PAL/SAL)
records the processors state. This record remains for the next reset
or for salinfo to transfer to disk. We can dump all the records in a
format somewhat similar to the output in /var/log/salinfo/decoded.

On more occasions than I could even begin to describe, those records
have helped us determine what the processor was doing despite it even
ignoring interrupts. This includes everything except when MCA/INIT
handling is disabled or PMIs are being processed.

If you could give this some consideration, I would appreciate it.
I really don't have the time to dedicate to thinking all the way through
and therefore will not stand in the way of any patch you propose.
If I can be of help in any way, please let me know.

Thanks,
Robin
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