The following patch removes the individual free area initialization from
free_area_init_core(), and puts it in a new function
zone_init_free_lists().  It also creates pages_to_bitmap_size(), which is
then used in zone_init_free_lists() as well as several times in my free
area bitmap resizing patch.

First of all, I think it looks nicer this way, but it's also necessary to
have this if you want to initialize a zone after system boot, like if a
NUMA node was hot-added.  In any case, it should be functionally equivalent
to the old code.

Compiles and boots on x86.  I've been running with this for a few weeks,
and haven't seen any problems with it yet.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>