Re: [PATCH] PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO

From: Rafael J. Wysocki
Date: Tue Sep 13 2016 - 20:54:29 EST

On Friday, September 09, 2016 10:43:32 AM Anisse Astier wrote:
> PAGE_POISONING_ZERO disables zeroing new pages on alloc, they are
> poisoned (zeroed) as they become available.
> In the hibernate use case, free pages will appear in the system without
> being cleared, left there by the loading kernel.
> This patch will make sure free pages are cleared on resume when
> PAGE_POISONING_ZERO is enabled. We free the pages just after resume
> because we can't do it later: going through any device resume code might
> allocate some memory and invalidate the free pages bitmap.
> Thus we don't need to disable hibernation when PAGE_POISONING_ZERO is
> enabled.
> Signed-off-by: Anisse Astier <anisse@xxxxxxxxx>
> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Cc: Laura Abbott <labbott@xxxxxxxxxxxxxxxxx>
> Cc: Mel Gorman <mgorman@xxxxxxx>
> Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>

Applied (with the tags from Pavel and Kees).