From 6dbe2747796899c9c302fb67e4bdcb1ca14a538c Mon Sep 17 00:00:00 2001 From: Jianyu Zhan Date: Wed, 14 May 2014 10:02:12 +1000 Subject: [PATCH] mm: fold mlocked_vma_newpage() into its only call site In previous commit(mm: use the light version __mod_zone_page_state in mlocked_vma_newpage()) a irq-unsafe __mod_zone_page_state is used. And as suggested by Andrew, to reduce the risks that new call sites incorrectly using mlocked_vma_newpage() without knowing they are adding racing, this patch folds mlocked_vma_newpage() into its only call site, page_add_new_anon_rmap, to make it open-cocded for people to know what is going on. Suggested-by: Andrew Morton Suggested-by: Hugh Dickins Signed-off-by: Jianyu Zhan Signed-off-by: Andrew Morton --- mm/internal.h | 29 ----------------------------- mm/rmap.c | 20 +++++++++++++++++--- 2 files changed, 17 insertions(+), 32 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index e067984bafa0..802c3a4fc03a 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -188,31 +188,6 @@ static inline void munlock_vma_pages_all(struct vm_area_struct *vma) munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end); } -/* - * Called only in fault path, to determine if a new page is being - * mapped into a LOCKED vma. If it is, mark page as mlocked. - */ -static inline int mlocked_vma_newpage(struct vm_area_struct *vma, - struct page *page) -{ - VM_BUG_ON_PAGE(PageLRU(page), page); - - if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) - return 0; - - if (!TestSetPageMlocked(page)) { - /* - * We use the irq-unsafe __mod_zone_page_stat because this - * counter is not modified from interrupt context, and the pte - * lock is held(spinlock), which implies preemption disabled. - */ - __mod_zone_page_state(page_zone(page), NR_MLOCK, - hpage_nr_pages(page)); - count_vm_event(UNEVICTABLE_PGMLOCKED); - } - return 1; -} - /* * must be called with vma's mmap_sem held for read or write, and page locked. */ @@ -255,10 +230,6 @@ extern unsigned long vma_address(struct page *page, struct vm_area_struct *vma); #endif #else /* !CONFIG_MMU */ -static inline int mlocked_vma_newpage(struct vm_area_struct *v, struct page *p) -{ - return 0; -} static inline void clear_page_mlock(struct page *page) { } static inline void mlock_vma_page(struct page *page) { } static inline void mlock_migrate_page(struct page *new, struct page *old) { } diff --git a/mm/rmap.c b/mm/rmap.c index 91b4d7869198..2dac0e206581 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1026,11 +1026,25 @@ void page_add_new_anon_rmap(struct page *page, __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, hpage_nr_pages(page)); __page_set_anon_rmap(page, vma, address, 1); - if (!mlocked_vma_newpage(vma, page)) { + + VM_BUG_ON_PAGE(PageLRU(page), page); + if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) { SetPageActive(page); lru_cache_add(page); - } else - add_page_to_unevictable_list(page); + return; + } + + if (!TestSetPageMlocked(page)) { + /* + * We use the irq-unsafe __mod_zone_page_stat because + * this counter is not modified from interrupt context, and the + * pte lock is held(spinlock), which implies preemption disabled. + */ + __mod_zone_page_state(page_zone(page), NR_MLOCK, + hpage_nr_pages(page)); + count_vm_event(UNEVICTABLE_PGMLOCKED); + } + add_page_to_unevictable_list(page); } /** -- 2.39.5