Re: dimm mapping

[Borislav Petkov <bp@alien8.de>]

On Wed, Dec 16, 2020 at 12:05:25PM -0500, Michael Di Domenico wrote:
> the problem i'm trying to solve is that when i run edac-util -v i
> don't get the dimm labels.  so when MCE trips it's chore to figure out
> which dimm it actually is when looking at the motherboard.  given that
> dmidecode seems to report the dimm labels, it seems odd that edac
> doesn't use them.  but then again i understand how all that's tied
> together (if at all).

Yeah, the short version is, there's no properly defined way for software
to read out DIMM silkscreen labels on each platform. I highly doubt that
is even possible. Perhaps some SMBUS interfaces or whatnot but firmware
is notoriosly buggy so there's no reliability there.

And, as said before, in some cases one cannot map back the physical
address reported with a DIMM MCE to the actual DIMM.

And, in recent times, OEM vendors do more and more RAS in the firmware
so the kernel doesn't get to even see some errors.

I'm always hoping that I'll be corrected some day but until then that's
the current situation, roughly.

-- 
Regards/Gruss,
    Boris.

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