Re: [PATCH V2] arm64/hotplug: Improve memory offline event notifier

From: Anshuman Khandual
Date: Mon Aug 24 2020 - 00:10:34 EST




On 08/24/2020 09:34 AM, Anshuman Khandual wrote:
> This brings about three different changes to the sole memory event notifier
> for arm64 platform and improves it's robustness while also enhancing debug
> capabilities during potential memory offlining error conditions.
>
> This moves the memory notifier registration bit earlier in the boot process
> from device_initcall() to setup_arch() which will help in guarding against
> potential early boot memory offline requests.
>
> This enables MEM_OFFLINE memory event handling. It will help intercept any
> possible error condition such as if boot memory some how still got offlined
> even after an expilicit notifier failure, potentially by a future change in
> generic hotplug framework. This would help detect such scenarious and help
> debug further.
>
> It also adds a validation function which scans entire boot memory and makes
> sure that early memory sections are online. This check is essential for the
> memory notifier to work properly as it cannot prevent boot memory offlining
> if they are not online to begin with. But this additional sanity check is
> enabled only with DEBUG_VM.
>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>

Wrong email address here for Will.

+ Will Deacon <will@xxxxxxxxxx>

s/will@xxxxxxxxxx/will@xxxxxxxxxx next time around.