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| author | Vlastimil Babka <vbabka@suse.cz> | 2016-03-15 14:56:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-15 16:55:16 -0700 |
| commit | 7dd80b8af0bcd705a9ef2fa272c082882616a499 (patch) | |
| tree | 75048a0e7ff2648c59b1a23640e202653fa1aa27 /mm/page_owner.c | |
| parent | 60f30350fd69a3e4d5f0f45937d3274c22565134 (diff) | |
| download | linux-stable-7dd80b8af0bcd705a9ef2fa272c082882616a499.tar.gz linux-stable-7dd80b8af0bcd705a9ef2fa272c082882616a499.tar.bz2 linux-stable-7dd80b8af0bcd705a9ef2fa272c082882616a499.zip | |
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>
Diffstat (limited to 'mm/page_owner.c')
| -rw-r--r-- | mm/page_owner.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mm/page_owner.c b/mm/page_owner.c index 7a37a30d941b..feaa28b40c1c 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; } |