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Commit d53a8b49 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
Browse files

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: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6a328a62

include/linux/rmap.h

+0 −36
Original line number Diff line number Diff line
@@ -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 */

mm/rmap.c

+0 −138
Original line number Diff line number Diff line
@@ -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 *@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;