mm/ksm: move [set_]page_stable_node from ksm.h to ksm.c

page_stable_node() and set_page_stable_node() are only used in mm/ksm.c
and there is no point to keep them in the include/linux/ksm.h

[akpm@linux-foundation.org: fix SYSFS=n build]
Link: http://lkml.kernel.org/r/1524552106-7356-3-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/ksm.h

@@ -37,17 +37,6 @@ static inline void ksm_exit(struct mm_struct *mm)
 		__ksm_exit(mm);
 }
 
-static inline struct stable_node *page_stable_node(struct page *page)
-{
-	return PageKsm(page) ? page_rmapping(page) : NULL;
-}
-
-static inline void set_page_stable_node(struct page *page,
-					struct stable_node *stable_node)
-{
-	page->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM);
-}
-
 /*
  * When do_swap_page() first faults in from swap what used to be a KSM page,
  * no problem, it will be assigned to this vma's anon_vma; but thereafter,

mm/ksm.c

@@ -840,6 +840,17 @@ static int unmerge_ksm_pages(struct vm_area_struct *vma,
 	return err;
 }
 
+static inline struct stable_node *page_stable_node(struct page *page)
+{
+	return PageKsm(page) ? page_rmapping(page) : NULL;
+}
+
+static inline void set_page_stable_node(struct page *page,
+					struct stable_node *stable_node)
+{
+	page->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM);
+}
+
 #ifdef CONFIG_SYSFS
 /*
  * Only called through the sysfs control interface: