power: add zone range overlapping check

There is a system thats node's pfns are overlapped as follows:

  -----pfn-------->
  N0 N1 N2 N0 N1 N2

Therefore, we need to care this overlapping when iterating pfn range.

mark_free_pages() iterates requested zone's pfn range and unset all
range's bitmap first.  And then it marks freepages in a zone to the
bitmap.  If there is an overlapping zone, above unset could clear
previous marked bit and reference to this bitmap in the future will
cause the problem.  To prevent it, this patch adds a zone check in
mark_free_pages().

Signed-off-by: Joonsoo Kim <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Michael Ellerman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 19fe7e9c39a6b4d0e50757cbf242a54ede0d0856..e132705d19fdbc2a55725863237638d5625189e1 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2156,6 +2156,10 @@ void mark_free_pages(struct zone *zone)
        for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
                if (pfn_valid(pfn)) {
                        page = pfn_to_page(pfn);
+
+                       if (page_zone(page) != zone)
+                               continue;
+
                        if (!swsusp_page_is_forbidden(page))
                                swsusp_unset_page_free(page);
                }