mm, page_owner: convert page_owner_inited to static key
CONFIG_PAGE_OWNER attempts to impose negligible runtime overhead when
enabled during compilation, but not actually enabled during runtime by
boot param page_owner=on. This overhead can be further reduced using
the static key mechanism, which this patch does.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
index cacaabe..8e2eb15 100644
--- a/include/linux/page_owner.h
+++ b/include/linux/page_owner.h
@@ -1,8 +1,10 @@
#ifndef __LINUX_PAGE_OWNER_H
#define __LINUX_PAGE_OWNER_H
+#include <linux/jump_label.h>
+
#ifdef CONFIG_PAGE_OWNER
-extern bool page_owner_inited;
+extern struct static_key_false page_owner_inited;
extern struct page_ext_operations page_owner_ops;
extern void __reset_page_owner(struct page *page, unsigned int order);
@@ -12,27 +14,23 @@
static inline void reset_page_owner(struct page *page, unsigned int order)
{
- if (likely(!page_owner_inited))
- return;
-
- __reset_page_owner(page, order);
+ if (static_branch_unlikely(&page_owner_inited))
+ __reset_page_owner(page, order);
}
static inline void set_page_owner(struct page *page,
unsigned int order, gfp_t gfp_mask)
{
- if (likely(!page_owner_inited))
- return;
-
- __set_page_owner(page, order, gfp_mask);
+ if (static_branch_unlikely(&page_owner_inited))
+ __set_page_owner(page, order, gfp_mask);
}
static inline gfp_t get_page_owner_gfp(struct page *page)
{
- if (likely(!page_owner_inited))
+ if (static_branch_unlikely(&page_owner_inited))
+ return __get_page_owner_gfp(page);
+ else
return 0;
-
- return __get_page_owner_gfp(page);
}
#else
static inline void reset_page_owner(struct page *page, unsigned int order)