EDAC k8 MC1: unknown syndrome

EDAC k8 MC1: unknown syndrome

[Phil Moors]

I'm getting these in the log:

EDAC k8 MC1: unknown syndrome 0x9391 - possible error reporting race
EDAC MC1: CE - no information available: k8_edac

>From looking about, I think that MC1 is memory controller 1 (on 2nd cpu)
and that CE is about error correction in ECC.

But is the error really reporting a DIMM problem or a race condition in
the kernel code handling ECC?

Thanks,
Phil

Re: EDAC k8 MC1: unknown syndrome

[Andi Kleen]

Phil Moors <pmoors@speakeasy.net> writes:
> 
> But is the error really reporting a DIMM problem or a race condition in
> the kernel code handling ECC?

First if you don't use a mainline kernel you should at least mention
it in the report.

It could well be a race -- the k8 DAC code is always racing against
the builtin machine check handler which reads the same registers.
That is why it was never accepted for mainline and shouldn't be used.

However these races should normally only cause lost events, not
bogus data, so it's probably something the CPU really reported
and EDAC doesn't understand.

The builtin machine check code will report all the same information
through mcelog (on x86-64) or syslog (on i386)

-Andi