Re: [PATCH] x86, amd, mce: Prevent potential cpu-online oops

From: Steffen Persvold
Date: Tue Apr 09 2013 - 05:45:56 EST


On 4/9/2013 11:38 AM, Borislav Petkov wrote:
On Tue, Apr 09, 2013 at 11:25:16AM +0200, Steffen Persvold wrote:
Why not let all cores just create their individual kobject and skip
this "shared" nb->bank4 concept ? Any disadvantage to that (apart from
the obvious storage bloat?).

Well, bank4 is shared across cores on the northbridge in *hardware*.

Well, yes I was aware of that :)

So it is only logical to represent the hardware layout correctly in
software.

Also, if you want to configure any settings over one core's sysfs nodes,
you want those to be visible across all cores automagically:

Hmm, yes of course. This of course breaks on our slave servers when the shared mechanism doesn't work properly (i.e NB not visible). Then all cores gets individual kobjects and there can be discrepancies between what the hardware is programmed to and what is reflected in /sys on some cores..

Ok, we go with our first approach to not create MC4 at all if NB isn't visible.

We'll redo the patch against the tip:x86/ras branch.

Cheers,
Steffen

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