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Subject[PATCH RFC 1/1] mm, page_alloc: fix incorrect zone_statistics data
Date
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@gmail.com>
---
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
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