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

From: Steffen Persvold
Date: Tue Apr 09 2013 - 05:26:20 EST


On 4/4/2013 9:07 PM, Borislav Petkov wrote:
On Thu, Apr 04, 2013 at 08:05:46PM +0200, Steffen Persvold wrote:
It made more sense (to me) to skip the creation of MC4 all together
if you can't find the matching northbridge since you can't reliably
do the dec_and_test() reference counting on the shared bank when you
don't have the common NB struct for all the shared cores.

Or am I just smoking the wrong stuff ?

No, actually *this* explanation should've been in the commit message.
You numascale people do crazy things with the hardware :) so explaining
yourself more verbosely is an absolute must if anyone is to understand
why you're changing the code.


Boris,

A question came up. Why have this "shared" bank concept for the kobjects at all ? What's the advantage ? Before our patch, when running on our architecture but without pci domains for "slave" servers, everything was working fine except the de-allocation oops due to the NULL pointer when offlining cores.

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?).

Cheers,
Steffen


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/