buddy: clarify comments describing buddy merge

In __free_one_page(), the comment "Move the buddy up one level" appears attached to the break and by implication when the break is taken we are moving it up one level:

if (!page_is_buddy(page, buddy, order))
break; /* Move the buddy up one level. */

In reality the inverse is true, we break out when we can no longer merge this page with its buddy. Looking back into pre-history (into the full git history) it appears that these two lines accidentally got joined as part of another change.

Move the comment down where it belongs below the if and clarify its language.

---
 mm/page_alloc.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

index 1575691..20e4c71 100644
@@ -459,8 +459,9 @@ static inline void __free_one_page(struct page *page,
 
 		buddy = __page_find_buddy(page, page_idx, order);
 		if (!page_is_buddy(page, buddy, order))
-			break;		/* Move the buddy up one level. */
+			break;
 
+		/* Our buddy is free, merge with it and move up one order. */
 		list_del(&buddy->lru);
 		zone->free_area[order].nr_free--;
 		rmv_page_order(buddy);

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>