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/mm/page_owner.c b/mm/page_owner.c
index 7a37a30..feaa28b 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -5,10 +5,11 @@
#include <linux/bootmem.h>
#include <linux/stacktrace.h>
#include <linux/page_owner.h>
+#include <linux/jump_label.h>
#include "internal.h"
static bool page_owner_disabled = true;
-bool page_owner_inited __read_mostly;
+DEFINE_STATIC_KEY_FALSE(page_owner_inited);
static void init_early_allocated_pages(void);
@@ -37,7 +38,7 @@
if (page_owner_disabled)
return;
- page_owner_inited = true;
+ static_branch_enable(&page_owner_inited);
init_early_allocated_pages();
}
@@ -147,7 +148,7 @@
struct page *page;
struct page_ext *page_ext;
- if (!page_owner_inited)
+ if (!static_branch_unlikely(&page_owner_inited))
return -EINVAL;
page = NULL;
@@ -295,7 +296,7 @@
{
struct dentry *dentry;
- if (!page_owner_inited) {
+ if (!static_branch_unlikely(&page_owner_inited)) {
pr_info("page_owner is disabled\n");
return 0;
}