linux-kernel - Re: [PATCH -v2 2/2] x86, MCE: Drop the default decoding notifier

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Date:	Mon, 25 Apr 2011 12:40:11 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Borislav Petkov <bp@...64.org>
Cc:	Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Tony Luck <tony.luck@...el.com>,
	EDAC devel <linux-edac@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Prarit Bhargava <prarit@...hat.com>,
	Nagananda Chumbalkar <Nagananda.Chumbalkar@...com>,
	Russ Anderson <rja@....com>
Subject: Re: [PATCH -v2 2/2] x86, MCE: Drop the default decoding notifier

Borislav Petkov <bp@...64.org> writes:

> On Tue, Apr 19, 2011 at 01:44:46PM -0400, Ingo Molnar wrote:
>> 
>> * Borislav Petkov <bp@...64.org> wrote:
>> 
>> > +	if (ret != NOTIFY_STOP)
>> > +		printk_ratelimited(KERN_EMERG HW_ERR
>> > +				   "Run the above through 'mcelog --ascii'\n");
>> 
>> pr_emerg_ratelimited() would allow you to keep that broken line happy?
>
> Not entirely. I had to do the exit-early-to-save-an-indentation-level
> trick also :)
>
> --
> From: Borislav Petkov <borislav.petkov@....com>
> Date: Wed, 13 Apr 2011 14:32:06 +0200
> Subject: [PATCH -v2.1 2/2] x86, MCE: Drop the default decoding notifier
>
> The default notifier doesn't make a lot of sense to call in the
> correctable errors case. Drop it and emit the mcelog decoding hint only
> in the uncorrectable errors case and when no notifier is registered.
> Also, limit issuing the "mcelog --ascii" message in the rare case when
> we dump unreported CEs before panicking.
>
> While at it, remove unused old x86_mce_decode_callback from the
> header.

Can we please print something if we please log something in the
case of a correctable error, when we only report it via mcelog?

I have a stupid recent intel cpu here that hits that case and without
the default x86_mce_decode_callback I wouldn't have even known that I am
getting something like 50 correctable errors an hour on one of my
machines.  In particular I am it hits so often I am seeing:
"mce_notify_irq: 2 callbacks suppressed".  I need to get those dimms
replaced soon because in a new product I simply can't imagine that many
correctable errors.

Eric
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