Simplify page_is_buddy() to reduce the redundant code for better code
readability.
Signed-off-by: chenqiwu <chenqiwu@xxxxxxxxxx>
---
changes in v4:
- change the return type of page_is_buddy() from int to bool.
- reflow the comment into fewer lines.
---
mm/page_alloc.c | 33 +++++++++++++--------------------
1 file changed, 13 insertions(+), 20 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3c4eb75..229fc8c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -791,32 +791,25 @@ static inline void set_page_order(struct page *page, unsigned int order)
*
* For recording page's order, we use page_private(page).
*/
-static inline int page_is_buddy(struct page *page, struct page *buddy,
+static inline bool page_is_buddy(struct page *page, struct page *buddy,
unsigned int order)
{
- if (page_is_guard(buddy) && page_order(buddy) == order) {
- if (page_zone_id(page) != page_zone_id(buddy))
- return 0;
-
- VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
+ if (!page_is_guard(buddy) && !PageBuddy(buddy))
+ return false;
- return 1;
- }
+ if (page_order(buddy) != order)
+ return false;
- if (PageBuddy(buddy) && page_order(buddy) == order) {
- /*
- * zone check is done late to avoid uselessly
- * calculating zone/node ids for pages that could
- * never merge.
- */
- if (page_zone_id(page) != page_zone_id(buddy))
- return 0;
+ /*
+ * zone check is done late to avoid uselessly calculating
+ * zone/node ids for pages that could never merge.
+ */
+ if (page_zone_id(page) != page_zone_id(buddy))
+ return false;
- VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
+ VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
- return 1;
- }
- return 0;
+ return true;
}
#ifdef CONFIG_COMPACTION
--
Acked-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
1.9.1
