[PATCH RFC 1/1] mm, page_alloc: fix incorrect zone_statistics data

[Jia He]

In commit b9f00e147f27 ("mm, page_alloc: reduce branches in
zone_statistics"), it reconstructed codes to reduce the branch miss rate.
Compared with the original logic, it assumed if !(flag & __GFP_OTHER_NODE)
 z->node would not be equal to preferred_zone->node. That seems to be
incorrect.

Fixes: commit b9f00e147f27 ("mm, page_alloc: reduce branches in
zone_statistics")

Signed-off-by: Jia He <hejianet@xxxxxxxxx>
---
 mm/page_alloc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6de9440..474757e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2568,6 +2568,9 @@ static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
 	if (z->node == local_nid) {
 		__inc_zone_state(z, NUMA_HIT);
 		__inc_zone_state(z, local_stat);
+	} else if (z->node == preferred_zone->node) {
+		__inc_zone_state(z, NUMA_HIT);
+		__inc_zone_state(z, NUMA_OTHER);
 	} else {
 		__inc_zone_state(z, NUMA_MISS);
 		__inc_zone_state(preferred_zone, NUMA_FOREIGN);
-- 
2.5.5