diff --git a/include/linux/damon.h b/include/linux/damon.h
index 7907918ad2e0..3fa96d7c9fe4 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -91,6 +91,12 @@ struct damon_target {
  * @DAMOS_LRU_DEPRIO:	Deprioritize the region on its LRU lists.
  * @DAMOS_STAT:		Do nothing but count the stat.
  * @NR_DAMOS_ACTIONS:	Total number of DAMOS actions
+ *
+ * The support of each action is up to running &struct damon_operations.
+ * &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR supports all actions except
+ * &enum DAMOS_LRU_PRIO and &enum DAMOS_LRU_DEPRIO.  &enum DAMON_OPS_PADDR
+ * supports only &enum DAMOS_PAGEOUT, &enum DAMOS_LRU_PRIO, &enum
+ * DAMOS_LRU_DEPRIO, and &DAMOS_STAT.
  */
 enum damos_action {
 	DAMOS_WILLNEED,