[PATCH 2/2] x86, apic: Disable BSP if boot cpu is AP

HATAYAMA Daisuke d.hatayama at jp.fujitsu.com
Mon Sep 9 02:18:06 EDT 2013


(2013/09/04 15:12), Borislav Petkov wrote:
> On Mon, Sep 02, 2013 at 06:42:44PM +0900, HATAYAMA Daisuke wrote:
>> The reason why I don't lookup BSP flag in MSR is that it's impossible.
>> To read MSR of some CPU, we need to use rdmsr instruction on the CPU.
>> However, in case of this issue, the BSP is halting or running in
>> the kdump 1st kernel.
>
> Yes, and on the AP, that flag would be cleared which makes it not a BSP.
>
>> A whole explanation is written in the patch description.
>
> Those tend to get lost in git history when a bunch of whitespace jerk
> offs appear ontop. So a nicely written comment in the code could be very
> helpful.
>
> Thanks.
>

Yes, that's the point this patch series misses. I'll describe the explanation
in Documentation/kexec/kexec.txt and point it in the comment of boot-up code.

-- 
Thanks.
HATAYAMA, Daisuke




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