Re: [PATCH v6 06/10] mm/memory_hotplug: Poison memmap in remove_pfn_range_from_zone()

From: Oscar Salvador
Date: Tue Feb 04 2020 - 04:00:04 EST


On Sun, Oct 06, 2019 at 10:56:42AM +0200, David Hildenbrand wrote:
> Let's poison the pages similar to when adding new memory in
> sparse_add_section(). Also call remove_pfn_range_from_zone() from
> memunmap_pages(), so we can poison the memmap from there as well.
>
> While at it, calculate the pfn in memunmap_pages() only once.
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>

Looks good to me, it is fine as long as we do not access those pages later on,
and if my eyes did not lie to me, we have to proper checks (pfn_to_online_page)
in place to avoid that, so:

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>

--
Oscar Salvador
SUSE L3