Re: [PATCH v2 2/2] mm,memory_hotplug: Fix shrink_{zone,node}_span

From: Dan Williams
Date: Wed Jul 17 2019 - 14:46:09 EST

On Wed, Jul 17, 2019 at 2:07 AM Oscar Salvador <osalvador@xxxxxxx> wrote:
> Since [1], shrink_{zone,node}_span work on PAGES_PER_SUBSECTION granularity.
> We need to adapt the loop that checks whether a zone/node contains only holes,
> and skip the whole range to be removed.
> Otherwise, since sub-sections belonging to the range to be removed have not yet
> been deactivated, pfn_valid() will return true on those and we will be left
> with a wrong accounting of spanned_pages, both for the zone and the node.
> Fixes: mmotm ("mm/hotplug: prepare shrink_{zone, pgdat}_span for sub-section removal")
> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>

Looks good,

Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>