From b20ce5e03b936be077463015661dcf52be274e5b Mon Sep 17 00:00:00 2001 From: Kirill A. Shutemov Date: Fri, 15 Jan 2016 16:54:37 -0800 Subject: 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 Cc: Vladimir Davydov Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Naoya Horiguchi Cc: Sasha Levin Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/util.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'mm/util.c') 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) -- cgit v1.2.3-55-g7522