mm: compaction: move list validation into compact_zone()

Move the cc.freepages and cc.migratepages list validation into compact_zone()
to remove some duplicate code.

Link: https://lkml.kernel.org/r/15cf54f7d762e87b04ac3cc74536f7d1ebbcd8cd.1673342761.git.baolin.wang@linux.alibaba.comSigned-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/compaction.c

@@ -2488,6 +2488,9 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
 
 	trace_mm_compaction_end(cc, start_pfn, end_pfn, sync, ret);
 
+	VM_BUG_ON(!list_empty(&cc->freepages));
+	VM_BUG_ON(!list_empty(&cc->migratepages));
+
 	return ret;
 }
 
@@ -2526,9 +2529,6 @@ static enum compact_result compact_zone_order(struct zone *zone, int order,
 
 	ret = compact_zone(&cc, &capc);
 
-	VM_BUG_ON(!list_empty(&cc.freepages));
-	VM_BUG_ON(!list_empty(&cc.migratepages));
-
 	/*
 	 * Make sure we hide capture control first before we read the captured
 	 * page pointer, otherwise an interrupt could free and capture a page
@@ -2659,9 +2659,6 @@ static void proactive_compact_node(pg_data_t *pgdat)
 		cc.zone = zone;
 
 		compact_zone(&cc, NULL);
-
-		VM_BUG_ON(!list_empty(&cc.freepages));
-		VM_BUG_ON(!list_empty(&cc.migratepages));
 	}
 }
 
@@ -2689,9 +2686,6 @@ static void compact_node(int nid)
 		cc.zone = zone;
 
 		compact_zone(&cc, NULL);
-
-		VM_BUG_ON(!list_empty(&cc.freepages));
-		VM_BUG_ON(!list_empty(&cc.migratepages));
 	}
 }
 
@@ -2868,9 +2862,6 @@ static void kcompactd_do_work(pg_data_t *pgdat)
 				     cc.total_migrate_scanned);
 		count_compact_events(KCOMPACTD_FREE_SCANNED,
 				     cc.total_free_scanned);
-
-		VM_BUG_ON(!list_empty(&cc.freepages));
-		VM_BUG_ON(!list_empty(&cc.migratepages));
 	}
 
 	/*