mm: memcontrol: move PageMemcgKmem to the scope of CONFIG_MEMCG_KMEM

The page only can be marked as kmem when CONFIG_MEMCG_KMEM is enabled.
So move PageMemcgKmem() to the scope of the CONFIG_MEMCG_KMEM.

As a bonus, on !CONFIG_MEMCG_KMEM build some code can be compiled out.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muchun Song <[email protected]>
Acked-by: Roman Gushchin <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Xiongchun Duan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 78ca34c935ab..bcf92b99f001 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -523,6 +523,7 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 }
 
+#ifdef CONFIG_MEMCG_KMEM
 /*
  * PageMemcgKmem - check if the page has MemcgKmem flag set
  * @page: a pointer to the page struct
@@ -537,7 +538,6 @@ static inline bool PageMemcgKmem(struct page *page)
 	return page->memcg_data & MEMCG_DATA_KMEM;
 }
 
-#ifdef CONFIG_MEMCG_KMEM
 /*
  * page_objcgs - get the object cgroups vector associated with a page
  * @page: a pointer to the page struct
@@ -579,6 +579,11 @@ static inline struct obj_cgroup **page_objcgs_check(struct page *page)
 }
 
 #else
+static inline bool PageMemcgKmem(struct page *page)
+{
+	return false;
+}
+
 static inline struct obj_cgroup **page_objcgs(struct page *page)
 {
 	return NULL;