diff options
| -rw-r--r-- | Documentation/vm/page_owner.txt | 9 | ||||
| -rw-r--r-- | include/linux/page_owner.h | 22 | ||||
| -rw-r--r-- | mm/page_owner.c | 9 | ||||
| -rw-r--r-- | mm/vmstat.c | 2 |
4 files changed, 21 insertions, 21 deletions
diff --git a/Documentation/vm/page_owner.txt b/Documentation/vm/page_owner.txt index 8f3ce9b..ffff143 100644 --- a/Documentation/vm/page_owner.txt +++ b/Documentation/vm/page_owner.txt @@ -28,10 +28,11 @@ with page owner and page owner is disabled in runtime due to no enabling boot option, runtime overhead is marginal. If disabled in runtime, it doesn't require memory to store owner information, so there is no runtime memory overhead. And, page owner inserts just two unlikely branches into -the page allocator hotpath and if it returns false then allocation is -done like as the kernel without page owner. These two unlikely branches -would not affect to allocation performance. Following is the kernel's -code size change due to this facility. +the page allocator hotpath and if not enabled, then allocation is done +like as the kernel without page owner. These two unlikely branches should +not affect to allocation performance, especially if the static keys jump +label patching functionality is available. Following is the kernel's code +size change due to this facility. - Without page owner text data bss dec hex filename 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 @@ extern gfp_t __get_page_owner_gfp(struct page *page); 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) 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 @@ static void init_page_owner(void) if (page_owner_disabled) return; - page_owner_inited = true; + static_branch_enable(&page_owner_inited); init_early_allocated_pages(); } @@ -147,7 +148,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) 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 @@ static int __init pageowner_init(void) { struct dentry *dentry; - if (!page_owner_inited) { + if (!static_branch_unlikely(&page_owner_inited)) { pr_info("page_owner is disabled\n"); return 0; } diff --git a/mm/vmstat.c b/mm/vmstat.c index 72c1798..69ce64f 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1120,7 +1120,7 @@ static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) #ifdef CONFIG_PAGE_OWNER int mtype; - if (!page_owner_inited) + if (!static_branch_unlikely(&page_owner_inited)) return; drain_all_pages(NULL); |