linux-kernel - Re: [PATCH v3] x86/mce: Try printing all machine check banks known before panic

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Date:	Sun, 23 Nov 2014 21:55:28 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	"Luck, Tony" <tony.luck@...el.com>
Cc:	rui wang <ruiv.wang@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"gong.chen@...ux.intel.com" <gong.chen@...ux.intel.com>,
	"Wang, Rui Y" <rui.y.wang@...el.com>
Subject: Re: [PATCH v3] x86/mce: Try printing all machine check banks known
 before panic

On Fri, Nov 21, 2014 at 09:59:49PM +0000, Luck, Tony wrote:
> > Oh, cpu errata. So this would mean that we can't even rely on the
> > contents of the MCA banks, can we?
> >
> > In any case, is any of the information in the MCA banks in such cases
> > even usable then? Because if not, we're definitely barking up the wrong
> > tree...
> 
> See above - I think even if there is a bug in the core that isn't setting the
> right bits in the MCi_STATUS register - we could get good data from
> devices out in the uncore.

Btw, since we're talking about errata - I guess you could use X86_BUG
and static_cpu_has_bug* to query in do_machine_check and modify logging
behavior of mce_log to bypass mce_severity and put all errors of the
last round in mce_log and then dump them out at panic time.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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