From d53a8b49a626fdfce4390710da6d04b4314db25f Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 24 Feb 2017 14:58:13 -0800 Subject: [PATCH] mm: drop page_check_address{,_transhuge} All users are gone. Let's drop them. Link: http://lkml.kernel.org/r/20170129173858.45174-12-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: Hillf Danton Cc: Hugh Dickins Cc: Johannes Weiner Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Srikar Dronamraju Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/rmap.h | 36 ----------- mm/rmap.c | 138 ------------------------------------------- 2 files changed, 174 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index b76343610653..8c89e902df3e 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -197,42 +197,6 @@ int page_referenced(struct page *, int is_locked, int try_to_unmap(struct page *, enum ttu_flags flags); -/* - * Used by uprobes to replace a userspace page safely - */ -pte_t *__page_check_address(struct page *, struct mm_struct *, - unsigned long, spinlock_t **, int); - -static inline pte_t *page_check_address(struct page *page, struct mm_struct *mm, - unsigned long address, - spinlock_t **ptlp, int sync) -{ - pte_t *ptep; - - __cond_lock(*ptlp, ptep = __page_check_address(page, mm, address, - ptlp, sync)); - return ptep; -} - -/* - * Used by idle page tracking to check if a page was referenced via page - * tables. - */ -#ifdef CONFIG_TRANSPARENT_HUGEPAGE -bool page_check_address_transhuge(struct page *page, struct mm_struct *mm, - unsigned long address, pmd_t **pmdp, - pte_t **ptep, spinlock_t **ptlp); -#else -static inline bool page_check_address_transhuge(struct page *page, - struct mm_struct *mm, unsigned long address, - pmd_t **pmdp, pte_t **ptep, spinlock_t **ptlp) -{ - *ptep = page_check_address(page, mm, address, ptlp, 0); - *pmdp = NULL; - return !!*ptep; -} -#endif - /* Avoid racy checks */ #define PVMW_SYNC (1 << 0) /* Look for migarion entries rather than present PTEs */ diff --git a/mm/rmap.c b/mm/rmap.c index 80525820aada..8774791e2809 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -708,144 +708,6 @@ out: return pmd; } -/* - * Check that @page is mapped at @address into @mm. - * - * If @sync is false, page_check_address may perform a racy check to avoid - * the page table lock when the pte is not present (helpful when reclaiming - * highly shared pages). - * - * On success returns with pte mapped and locked. - */ -pte_t *__page_check_address(struct page *page, struct mm_struct *mm, - unsigned long address, spinlock_t **ptlp, int sync) -{ - pmd_t *pmd; - pte_t *pte; - spinlock_t *ptl; - - if (unlikely(PageHuge(page))) { - /* when pud is not present, pte will be NULL */ - pte = huge_pte_offset(mm, address); - if (!pte) - return NULL; - - ptl = huge_pte_lockptr(page_hstate(page), mm, pte); - goto check; - } - - pmd = mm_find_pmd(mm, address); - if (!pmd) - return NULL; - - pte = pte_offset_map(pmd, address); - /* Make a quick check before getting the lock */ - if (!sync && !pte_present(*pte)) { - pte_unmap(pte); - return NULL; - } - - ptl = pte_lockptr(mm, pmd); -check: - spin_lock(ptl); - if (pte_present(*pte) && page_to_pfn(page) == pte_pfn(*pte)) { - *ptlp = ptl; - return pte; - } - pte_unmap_unlock(pte, ptl); - return NULL; -} - -#ifdef CONFIG_TRANSPARENT_HUGEPAGE -/* - * Check that @page is mapped at @address into @mm. In contrast to - * page_check_address(), this function can handle transparent huge pages. - * - * On success returns true with pte mapped and locked. For PMD-mapped - * transparent huge pages *@ptep is set to NULL. - */ -bool page_check_address_transhuge(struct page *page, struct mm_struct *mm, - unsigned long address, pmd_t **pmdp, - pte_t **ptep, spinlock_t **ptlp) -{ - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - spinlock_t *ptl; - - if (unlikely(PageHuge(page))) { - /* when pud is not present, pte will be NULL */ - pte = huge_pte_offset(mm, address); - if (!pte) - return false; - - ptl = huge_pte_lockptr(page_hstate(page), mm, pte); - pmd = NULL; - goto check_pte; - } - - pgd = pgd_offset(mm, address); - if (!pgd_present(*pgd)) - return false; - pud = pud_offset(pgd, address); - if (!pud_present(*pud)) - return false; - pmd = pmd_offset(pud, address); - - if (pmd_trans_huge(*pmd)) { - ptl = pmd_lock(mm, pmd); - if (!pmd_present(*pmd)) - goto unlock_pmd; - if (unlikely(!pmd_trans_huge(*pmd))) { - spin_unlock(ptl); - goto map_pte; - } - - if (pmd_page(*pmd) != page) - goto unlock_pmd; - - pte = NULL; - goto found; -unlock_pmd: - spin_unlock(ptl); - return false; - } else { - pmd_t pmde = *pmd; - - barrier(); - if (!pmd_present(pmde) || pmd_trans_huge(pmde)) - return false; - } -map_pte: - pte = pte_offset_map(pmd, address); - if (!pte_present(*pte)) { - pte_unmap(pte); - return false; - } - - ptl = pte_lockptr(mm, pmd); -check_pte: - spin_lock(ptl); - - if (!pte_present(*pte)) { - pte_unmap_unlock(pte, ptl); - return false; - } - - /* THP can be referenced by any subpage */ - if (pte_pfn(*pte) - page_to_pfn(page) >= hpage_nr_pages(page)) { - pte_unmap_unlock(pte, ptl); - return false; - } -found: - *ptep = pte; - *pmdp = pmd; - *ptlp = ptl; - return true; -} -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ - struct page_referenced_arg { int mapcount; int referenced; -- 2.20.1