linux-kernel - Re: [PATCH 1/2] MCE, AMD: Make MC2 decoding part of amd_decoder

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Date:	Mon, 17 Dec 2012 21:05:35 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Joe Perches <joe@...ches.com>
Cc:	Jacob Shin <jacob.shin@....com>,
	Doug Thompson <dougthompson@...ssion.com>,
	linux-edac@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] MCE, AMD: Make MC2 decoding part of amd_decoder_ops
 as well

On Mon, Dec 17, 2012 at 11:57:01AM -0800, Joe Perches wrote:
> It'd be better to change the pr_cont uses to pr_emerg
> 
> []
> 
> > +static void decode_mc2_mce(struct mce *m)
> > +{
> > +	u16 ec = EC(m->status);
> > +	u8 xec = XEC(m->status, xec_mask);
> > +
> > +	pr_emerg(HW_ERR "MC2 Error: ");
> 
> Remove this and
> 
> > +	if (fam_ops->mc2_mce(ec, xec))
> > +		;
> > +	else
> > +		pr_emerg(HW_ERR "Corrupted MC2 MCE info?\n");
> >  }
> 
> And make this
> 
> 	if (!fam_ops->mc2_mce(ec, xec))
> 		pr_emerg(etc...);

No, this is not how we do this here. We do pr_emerg in the main per-bank
function, i.e. mc0, mc1, mc2... and we finish the line in the respective
function with pr_cont.

If your fear is line interleaving, then this shouldn't happen in most
cases because we're in atomic #MC context and nothing else is executing
in that case. (And I haven't seen it interleave in all my testing so
far).

If it does interleave when we have a non-critical error detected and
reported in process context, then this whole decoding code needs a lot
more work than this.

Thanks.

-- 
Regards/Gruss,
    Boris.

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