Re: [PATCH v2 02/10] mm/memory_hotplug: enforce section granularity when onlining/offlining

[Oscar Salvador]

On Wed, Aug 19, 2020 at 07:59:49PM +0200, David Hildenbrand wrote:
> Already two people (including me) tried to offline subsections, because
> the function looks like it can deal with it. But we really can only
> online/offline full sections that are properly aligned (e.g., we can only
> mark full sections online/offline via SECTION_IS_ONLINE).
> 
> Add a simple safety net to document the restriction now. Current users
> (core and powernv/memtrace) respect these restrictions.

It's been a while since I looked at sub-section handling stuff so sorry to ask
this, but was it true that we can hot-{remove,add} sub-section granularity, while
we can only online /offline on section granularity?

> 
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
> Cc: Baoquan He <bhe@xxxxxxxxxx>
> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>


-- 
Oscar Salvador
SUSE L3