mm: compaction: avoid fragmentation score calculation for empty zones

There is no need to calculate the fragmentation score for empty zones.

Link: https://lkml.kernel.org/r/100331ad9d274a9725e687b00d85d75d7e4a17c7.1673342761.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/compaction.c b/mm/compaction.c
index 0fd6c81a78099e39e9a3a67154da0715d592af5b..b758b00a4885458f9411a7e261bda4260e9d8004 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2025,6 +2025,8 @@ static unsigned int fragmentation_score_node(pg_data_t *pgdat)
                struct zone *zone;
 
                zone = &pgdat->node_zones[zoneid];
+               if (!populated_zone(zone))
+                       continue;
                score += fragmentation_score_zone_weighted(zone);
        }