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Message-Id: <20170124162824.91275-12-kirill.shutemov@linux.intel.com>
Date: Tue, 24 Jan 2017 19:28:23 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Andrea Arcangeli <aarcange@...hat.com>,
Hugh Dickins <hughd@...gle.com>,
Rik van Riel <riel@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH 11/12] mm: drop page_check_address{,_transhuge}
All users are gone. Let's drop them.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
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 474279810742..74113df9418d 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -196,42 +196,6 @@ 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 PAGE_CHECK_WALK_SYNC (1 << 0)
/* Look for migarion entries rather than present ptes */
diff --git a/mm/rmap.c b/mm/rmap.c
index cb34fd68a23a..7106eb9b37a8 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -708,144 +708,6 @@ pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
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 *@...p 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;
--
2.11.0
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