mm/page_alloc: fix the range check for backward merging
The current check for 'backward merging' within add_active_range() does
not seem correct. start_pfn must be compared against
early_node_map[i].start_pfn (and NOT against .end_pfn) to find out whether
the new region is backward-mergeable with the existing range.
Signed-off-by: Kazuhisa Ichikawa <ki@epsilou.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e9f5cc..6ea4966 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3998,7 +3998,7 @@
}
/* Merge backward if suitable */
- if (start_pfn < early_node_map[i].end_pfn &&
+ if (start_pfn < early_node_map[i].start_pfn &&
end_pfn >= early_node_map[i].start_pfn) {
early_node_map[i].start_pfn = start_pfn;
return;
