Re: [PATCH 1/2] ia64 kdump: add kdump_on_fatal_mca

[Jay Lan <jlan@sgi.com>]

Russ Anderson wrote:
> On Tue, Apr 08, 2008 at 10:51:42AM -0700, Luck, Tony wrote:
>>> I think kdump_on_fatal_mca should be set to 1 by default. Fatal
>>> mca is exactly the case where we need a dump to analyze the problem.
>> I'm not so sure.  If the fatal MCA was caused by the s/w doing something
>> wrong (e.g. accessing non-existant memory), then a dump is useful to find out
>> what went wrong.
>>
>> But if the MCA was caused by some h/w error (e.g. 2xECC bit error in kernel
>> memory), then a dump won't help.
>>
>> Perhaps the dump would help distinguish the s/w case from the h/w case?
> 
> Yes.  We generally try to take a dump after a crash to collect all
> the available data.  The analysis of the data (to determine h/w or
> s/w) occurs after the reboot.
> 
> As an alternative, could kdump_on_fatal_mca be turned on by 
> default in Altix (in the Altix specific boot code)?  Then
> we could set our default without impacting other vendors.

Yes, Propack can set the configuration on Altix. I saw the proposed
patch that changes the current behavior without mentioning it
at the summary, so i brought it up. ;)

- jay

> 
> Thanks,