On Thu 2016-08-11 23:23:20, Rafael J. Wysocki wrote:

On Thursday, August 11, 2016 11:06:15 PM Pavel Machek wrote:

quoted

Hi!

quoted

From: Rafael J. Wysocki <redacted>

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?

This is more about making it easier to debug than about speed, TBH.

Avoiding bitmap operations and the mm subsystem involvement reduces
complexity and the number of places to look into in case something goes
wrong.

Well, it looked like 3/3 just added code and did not remove anything,
so I fail to see how it makes code easier to follow...

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
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