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

From: Borislav Petkov
Date: Wed Sep 04 2013 - 02:12:03 EST


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.

--
Regards/Gruss,
Boris.
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