If move_freepages() returns 0 because zone_spans_pfn(), *num_movable can
hold the value from the stack because it does not get initialized in
move_freepages().
Move the initialization to move_freepages_block() to guarantee the value
actually makes sense.
This currently doesn't affect its only caller where num_movable != NULL,
so no bug fix, but just more robust.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
---
mm/page_alloc.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2015,10 +2015,6 @@ static int move_freepages(struct zone *zone,
pfn_valid(page_to_pfn(end_page)) &&
page_zone(start_page) != page_zone(end_page));
#endif
-
- if (num_movable)
- *num_movable = 0;
-
for (page = start_page; page <= end_page;) {
if (!pfn_valid_within(page_to_pfn(page))) {
page++;
@@ -2058,6 +2054,9 @@ int move_freepages_block(struct zone *zone, struct page *page,
unsigned long start_pfn, end_pfn;
struct page *start_page, *end_page;
+ if (num_movable)
+ *num_movable = 0;
+
start_pfn = page_to_pfn(page);
start_pfn = start_pfn & ~(pageblock_nr_pages-1);
start_page = pfn_to_page(start_pfn);
