Re: [PATCH v4 0/3] x86, apic, kexec: Add disable_cpu_apic kernelparameter

From: HATAYAMA Daisuke
Date: Thu Oct 31 2013 - 00:46:12 EST

(2013/10/31 9:58), jerry.hoemann@xxxxxx wrote:
On Wed, Oct 23, 2013 at 09:05:06AM +0900, HATAYAMA Daisuke wrote:

- Rebased on top of v3.12-rc6

- Basic design has been changed. Now users need to figure out initial
APIC ID of BSP in the 1st kernel and configures kernel parameter for
the 2nd kernel manually using disable_cpu_apic kernel parameter to
be newly introduced in this patch set. This design is more flexible
than the previous version in that we no longer have to rely on
ACPI/MP table to get initial APIC ID of BSP.

Do you literally mean a human at each boot will have to configure
the kdump configuration files for passing disable_cpu_apic?
Or do you envision the setting of disable_cpu_apic being put into
the kdump initialization scripts?



Nearer to the former case, but this is not what a human should do. It's
a cumbersome task. I think, on fedora/RHEL system for example, kdump
service should check at each boot automatically.



Are you planning on making changes to the kexec tools to automate
the setting of disable_cpu_apic to the capture kernel? Or do you
know someone who is planning this?

I back ported the kernel side changes to a 4.2.32 based kernel.
I tested the patch on a prototype system which exhibits a stable
initial_apic_id for CPU 0. While not something that would be suitable
for customers, it does allow me to test the kernel portion of the patch.

I will report the results of the testing later this week.

I'll do that after this patch is merged in kernel. But it is still under


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