From 010c164a5fa7e169deab0a4d8211611f1930c1cd Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 23 Sep 2019 15:38:19 -0700 Subject: mm: move memcmp_pages() and pages_identical() Patch series "THP aware uprobe", v13. This patchset makes uprobe aware of THPs. Currently, when uprobe is attached to text on THP, the page is split by FOLL_SPLIT. As a result, uprobe eliminates the performance benefit of THP. This set makes uprobe THP-aware. Instead of FOLL_SPLIT, we introduces FOLL_SPLIT_PMD, which only split PMD for uprobe. After all uprobes within the THP are removed, the PTE-mapped pages are regrouped as huge PMD. This set (plus a few THP patches) is also available at https://github.com/liu-song-6/linux/tree/uprobe-thp This patch (of 6): Move memcmp_pages() to mm/util.c and pages_identical() to mm.h, so that we can use them in other files. Link: http://lkml.kernel.org/r/20190815164525.1848545-2-songliubraving@fb.com Signed-off-by: Song Liu Acked-by: Kirill A. Shutemov Reviewed-by: Oleg Nesterov Cc: Johannes Weiner Cc: Matthew Wilcox Cc: William Kucharski Cc: Srikar Dronamraju Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 57a9fa34f159..0ac87d9ee9d8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2868,5 +2868,12 @@ void __init setup_nr_node_ids(void); static inline void setup_nr_node_ids(void) {} #endif +extern int memcmp_pages(struct page *page1, struct page *page2); + +static inline int pages_identical(struct page *page1, struct page *page2) +{ + return !memcmp_pages(page1, page2); +} + #endif /* __KERNEL__ */ #endif /* _LINUX_MM_H */ -- cgit v1.2.3