[PATCH v2 06/29] mm/zsmalloc: make PageZsmalloc() sticky until the page is freed

[David Hildenbrand]

Let the page freeing code handle clearing the page type. Being able to
identify balloon pages until actually freed is a requirement for
upcoming movable_ops migration changes.

Acked-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Acked-by: Harry Yoo <harry.yoo@xxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 mm/zpdesc.h   | 5 -----
 mm/zsmalloc.c | 4 ++--
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/mm/zpdesc.h b/mm/zpdesc.h
index 5cb7e3de43952..5763f36039736 100644
--- a/mm/zpdesc.h
+++ b/mm/zpdesc.h
@@ -163,11 +163,6 @@ static inline void __zpdesc_set_zsmalloc(struct zpdesc *zpdesc)
 	__SetPageZsmalloc(zpdesc_page(zpdesc));
 }
 
-static inline void __zpdesc_clear_zsmalloc(struct zpdesc *zpdesc)
-{
-	__ClearPageZsmalloc(zpdesc_page(zpdesc));
-}
-
 static inline struct zone *zpdesc_zone(struct zpdesc *zpdesc)
 {
 	return page_zone(zpdesc_page(zpdesc));
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 7f1431f2be98f..626f09fb27138 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -244,6 +244,7 @@ static inline void free_zpdesc(struct zpdesc *zpdesc)
 {
 	struct page *page = zpdesc_page(zpdesc);
 
+	/* PageZsmalloc is sticky until the page is freed to the buddy. */
 	__free_page(page);
 }
 
@@ -880,7 +881,7 @@ static void reset_zpdesc(struct zpdesc *zpdesc)
 	ClearPagePrivate(page);
 	zpdesc->zspage = NULL;
 	zpdesc->next = NULL;
-	__ClearPageZsmalloc(page);
+	/* PageZsmalloc is sticky until the page is freed to the buddy. */
 }
 
 static int trylock_zspage(struct zspage *zspage)
@@ -1055,7 +1056,6 @@ static struct zspage *alloc_zspage(struct zs_pool *pool,
 		if (!zpdesc) {
 			while (--i >= 0) {
 				zpdesc_dec_zone_page_state(zpdescs[i]);
-				__zpdesc_clear_zsmalloc(zpdescs[i]);
 				free_zpdesc(zpdescs[i]);
 			}
 			cache_free_zspage(pool, zspage);
-- 
2.49.0