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Commit 3fe87967 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
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mm: convert remove_migration_pte() to use page_vma_mapped_walk() 

remove_migration_pte() also can easily be converted to
page_vma_mapped_walk().

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170129173858.45174-13-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 d53a8b49

mm/migrate.c

+41 −61
Original line number Diff line number Diff line
@@ -193,52 +193,33 @@ void putback_movable_pages(struct list_head *l) 
/*

 * Restore a potential migration pte to a working pte entry

 */

static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,

static int remove_migration_pte(struct page *page, struct vm_area_struct *vma,

				 unsigned long addr, void *old)

{

	struct mm_struct *mm = vma->vm_mm;

	struct page_vma_mapped_walk pvmw = {

		.page = old,

		.vma = vma,

		.address = addr,

		.flags = PVMW_SYNC | PVMW_MIGRATION,

	};

	struct page *new;

	pte_t pte;

	swp_entry_t entry;

 	pmd_t *pmd;

	pte_t *ptep, pte;

 	spinlock_t *ptl;



	if (unlikely(PageHuge(new))) {

		ptep = huge_pte_offset(mm, addr);

		if (!ptep)

			goto out;

		ptl = huge_pte_lockptr(hstate_vma(vma), mm, ptep);

	} else {

		pmd = mm_find_pmd(mm, addr);

		if (!pmd)

			goto out;



		ptep = pte_offset_map(pmd, addr);



		/*

		 * Peek to check is_swap_pte() before taking ptlock?  No, we

		 * can race mremap's move_ptes(), which skips anon_vma lock.

		 */



		ptl = pte_lockptr(mm, pmd);

	}



 	spin_lock(ptl);

	pte = *ptep;

	if (!is_swap_pte(pte))

		goto unlock;



	entry = pte_to_swp_entry(pte);



	if (!is_migration_entry(entry) ||

	    migration_entry_to_page(entry) != old)

		goto unlock;

	VM_BUG_ON_PAGE(PageTail(page), page);

	while (page_vma_mapped_walk(&pvmw)) {

		new = page - pvmw.page->index +

			linear_page_index(vma, pvmw.address);



		get_page(new);

		pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));

	if (pte_swp_soft_dirty(*ptep))

		if (pte_swp_soft_dirty(*pvmw.pte))

			pte = pte_mksoft_dirty(pte);



	/* Recheck VMA as permissions can change since migration started  */

		/*

		 * Recheck VMA as permissions can change since migration started

		 */

		entry = pte_to_swp_entry(*pvmw.pte);

		if (is_write_migration_entry(entry))

			pte = maybe_mkwrite(pte, vma);
@@ -249,15 +230,15 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, 
		}

#endif

		flush_dcache_page(new);

	set_pte_at(mm, addr, ptep, pte);

		set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);



		if (PageHuge(new)) {

			if (PageAnon(new))

			hugepage_add_anon_rmap(new, vma, addr);

				hugepage_add_anon_rmap(new, vma, pvmw.address);

			else

				page_dup_rmap(new, true);

		} else if (PageAnon(new))

		page_add_anon_rmap(new, vma, addr, false);

			page_add_anon_rmap(new, vma, pvmw.address, false);

		else

			page_add_file_rmap(new, false);
@@ -265,10 +246,9 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma, 
			mlock_vma_page(new);



		/* No need to invalidate - it was non-present before */

	update_mmu_cache(vma, addr, ptep);

unlock:

	pte_unmap_unlock(ptep, ptl);

out:

		update_mmu_cache(vma, pvmw.address, pvmw.pte);

	}



	return SWAP_AGAIN;

}