Subject: Re: [PATCH] powerpc: on crash, kexec'ed kernel needs all CPUs are online

From: Benjamin Herrenschmidt <[email-masked]>
Date: Sat, 17 Oct 2015 07:33:53 +0530

On Fri, 2015-10-16 at 09:57 +0200, Laurent Vivier wrote:
> For me the problem is: as these CPUs are offline, I guess the core has
> been switched to 1 thread per core, so the CPUs (1 to 7 for core 0)
> don't exist anymore, how can we return them to OPAL ?

Another option is to make the new kernel kick_cpu fallback, if it knows
it's coming as a crashdump, to sending IPIs.

We would need some sane way to catch the guys coming it at 0x100 and
route the to secondary start.

Cheers,
Ben.