Re: [PATCH v2 3/3] PM / hibernate: Recycle safe pages after image restoration

From: Pavel Machek
Date: Thu Aug 11 2016 - 17:06:28 EST


Hi!

> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> One of the memory bitmaps used by the hibernation image restoration
> code is freed after the image has been loaded.
>
> That is not quite efficient, though, because the memory pages used
> for building that bitmap are known to be safe (ie. they were not
> used by the image kernel before hibernation) and the arch-specific
> code finalizing the image restoration may need them. In that case
> it needs to allocate those pages again via the memory management
> subsystem, check if they are really safe again by consulting the
> other bitmaps and so on.
>
> To avoid that, recycle those pages by putting them into the global
> list of known safe pages so that they can be given to the arch code
> right away when necessary.

Ok, so you are trying to gain speed here? How much is the speedup?

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html