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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-01-15 16:54:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-15 17:56:32 -0800
commitb20ce5e03b936be077463015661dcf52be274e5b (patch)
tree1004a054c0263a471ef79a7cd84fea904a71b655 /mm/util.c
parente90309c9f7722db4ff5bce3b9e6e04d1460f2553 (diff)
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mm: prepare page_referenced() and page_idle to new THP refcounting
Both page_referenced() and page_idle_clear_pte_refs_one() assume that THP can only be mapped with PMD, so there's no reason to look on PTEs for PageTransHuge() pages. That's no true anymore: THP can be mapped with PTEs too. The patch removes PageTransHuge() test from the functions and opencode page table check. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/util.c')
-rw-r--r--mm/util.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c
index 8acb936a52c8..6d1f9200f74e 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -407,6 +407,20 @@ struct address_space *page_mapping(struct page *page)
return mapping;
}
+/* Slow path of page_mapcount() for compound pages */
+int __page_mapcount(struct page *page)
+{
+ int ret;
+
+ ret = atomic_read(&page->_mapcount) + 1;
+ page = compound_head(page);
+ ret += atomic_read(compound_mapcount_ptr(page)) + 1;
+ if (PageDoubleMap(page))
+ ret--;
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__page_mapcount);
+
int overcommit_ratio_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)