From 21333b2b66b805a360641568588e5a0bb06d9d1f Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 21 Sep 2009 17:01:59 -0700 Subject: ksm: no debug in page_dup_rmap() page_dup_rmap(), used on each mapped page when forking, was originally just an inline atomic_inc of mapcount. 2.6.22 added CONFIG_DEBUG_VM out-of-line checks to it, which would need to be ever-so-slightly complicated to allow for the PageKsm() we're about to define. But I think these checks never caught anything. And if it's coding errors we're worried about, such checks should be in page_remove_rmap() too, not just when forking; whereas if it's pagetable corruption we're worried about, then they shouldn't be limited to CONFIG_DEBUG_VM. Oh, just revert page_dup_rmap() to an inline atomic_inc of mapcount. Signed-off-by: Hugh Dickins Signed-off-by: Chris Wright Signed-off-by: Izik Eidus Cc: Nick Piggin Cc: Andrea Arcangeli Cc: Rik van Riel Cc: Wu Fengguang Cc: Balbir Singh Cc: Hugh Dickins Cc: KAMEZAWA Hiroyuki Cc: Lee Schermerhorn Cc: Avi Kivity Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/rmap.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/rmap.h b/include/linux/rmap.h index bf116d0dbf2..477841d29fc 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -71,14 +71,10 @@ void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned lon void page_add_file_rmap(struct page *); void page_remove_rmap(struct page *); -#ifdef CONFIG_DEBUG_VM -void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address); -#else -static inline void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address) +static inline void page_dup_rmap(struct page *page) { atomic_inc(&page->_mapcount); } -#endif /* * Called from mm/vmscan.c to handle paging out -- cgit v1.2.3