[PATCH] mm: make some vars and functions static or __init

[Ting Liu <liuting.0x7c00@bytedance.com>]

From: "liuting.0x7c00" <liuting.0x7c00@bytedance.com>

"page_idle_ops" as a global var, but its scope of use within this
document. So it should be static.
"page_ext_ops" is a var used in the kernel initial phase. And other
functions are aslo used in the kernel initial phase. So they should be
__init or __initdata to reclaim memory.

Signed-off-by: liuting.0x7c00 <liuting.0x7c00@bytedance.com>
---
 include/linux/page_idle.h | 1 -
 mm/page_ext.c             | 4 ++--
 mm/page_owner.c           | 4 ++--
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/include/linux/page_idle.h b/include/linux/page_idle.h
index 83abf95e9fa7..4663dfed1293 100644
--- a/include/linux/page_idle.h
+++ b/include/linux/page_idle.h
@@ -13,7 +13,6 @@
  * If there is not enough space to store Idle and Young bits in page flags, use
  * page ext flags instead.
  */
-extern struct page_ext_operations page_idle_ops;
 
 static inline bool folio_test_young(struct folio *folio)
 {
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 6242afb24d84..2193e3f10e56 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -63,12 +63,12 @@ static bool need_page_idle(void)
 {
 	return true;
 }
-struct page_ext_operations page_idle_ops = {
+static struct page_ext_operations page_idle_ops = {
 	.need = need_page_idle,
 };
 #endif
 
-static struct page_ext_operations *page_ext_ops[] = {
+static struct page_ext_operations *page_ext_ops[] __initdata = {
 #ifdef CONFIG_PAGE_OWNER
 	&page_owner_ops,
 #endif
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 4f924957ce7a..5eea061bb1e5 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -46,7 +46,7 @@ static int __init early_page_owner_param(char *buf)
 }
 early_param("page_owner", early_page_owner_param);
 
-static bool need_page_owner(void)
+static __init bool need_page_owner(void)
 {
 	return page_owner_enabled;
 }
@@ -75,7 +75,7 @@ static noinline void register_early_stack(void)
 	early_handle = create_dummy_stack();
 }
 
-static void init_page_owner(void)
+static __init void init_page_owner(void)
 {
 	if (!page_owner_enabled)
 		return;
-- 
2.20.1