RE: [PATCH v3 1/2] x86, mce, severity: extend the the mce_severity mechanism to handle UCNA/DEFERRED error

From: Luck, Tony
Date: Mon Nov 10 2014 - 18:32:20 EST


But then I tested it ...

I injected a UC error to memory - then did a simple byte write to the target line.
This resulted in two banks logging errors:

[ 124.638045] poll: CPU54 saw ec00000000010092 in bank 7
[ 124.639006] poll: severity = 0
[ 124.647333] poll: CPU54 saw b800000000200179 in bank 3
[ 124.648322] poll: severity = 1

The bank 7 error reported as severity 0 because EN=0 ... so we took no action for it.

The bank 3 error got past that hurdle, then through the next BIT(8) set indicates a
cache error. Fell at the last check because ADDRV=0.


I think the severity table entry for the "EN" check should have been skipped
when calling from the CMCI handler. Then we would have seen severity=1
from the bank 7 error. It would have passed the other tests too (BIT(7) and
ADDRV).

-Tony