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

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Date:	Mon, 17 Dec 2012 12:16:16 -0800
From:	Joe Perches <joe@...ches.com>
To:	Borislav Petkov <bp@...en8.de>
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, 2012-12-17 at 21:05 +0100, Borislav Petkov wrote:
> 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.
> 

You also have paths where you start a pr_emerg and do not terminate
it when there is no apparent error at all.


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