Le 12 sept. 2016 13:32, "Pavel Machek" <pavel@ucw.cz> a écrit :
>
> On Fri 2016-09-09 10:43:32, 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@astier.eu>
> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > Cc: Laura Abbott <labbott@fedoraproject.org>
> > Cc: Mel Gorman <mgorman@suse.de>
> > Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
>
> Looks reasonable to me.
>
> Acked-by: Pavel Machek <pavel@ucw.cz>
>
> Actually.... this takes basically zero time come. Do we want to do it
> unconditionally?
>
> (Yes, it is free memory, but for sake of debugging, I guess zeros are
> preffered to random content that changed during hibernation.)
>
> (But that does not change the Ack.)
>
> Best regards,
>
Pavel
> --

I have no opposition on doing this unconditionally. I can send a v2 as soon
as I get closer to a computer.

Regards,

Anisse

Sorry for the brevity, I'm posting this on mobile.