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Commit f27176cf authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds
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mm: convert page_mkclean_one() to use page_vma_mapped_walk() 

For consistency, it worth converting all page_check_address() to
page_vma_mapped_walk(), so we could drop the former.

PMD handling here is future-proofing, we don't have users yet.  ext4
with huge pages will be the first.

Link: http://lkml.kernel.org/r/20170129173858.45174-7-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 a8fa41ad

mm/rmap.c

+45 −23
Original line number Diff line number Diff line
@@ -1017,34 +1017,56 @@ int page_referenced(struct page *page, 
static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,

			    unsigned long address, void *arg)

{

	struct mm_struct *mm = vma->vm_mm;

	pte_t *pte;

	spinlock_t *ptl;

	int ret = 0;

	struct page_vma_mapped_walk pvmw = {

		.page = page,

		.vma = vma,

		.address = address,

		.flags = PVMW_SYNC,

	};

	int *cleaned = arg;



	pte = page_check_address(page, mm, address, &ptl, 1);

	if (!pte)

		goto out;



	if (pte_dirty(*pte) || pte_write(*pte)) {

	while (page_vma_mapped_walk(&pvmw)) {

		int ret = 0;

		address = pvmw.address;

		if (pvmw.pte) {

			pte_t entry;

			pte_t *pte = pvmw.pte;



			if (!pte_dirty(*pte) && !pte_write(*pte))

				continue;



			flush_cache_page(vma, address, pte_pfn(*pte));

			entry = ptep_clear_flush(vma, address, pte);

			entry = pte_wrprotect(entry);

			entry = pte_mkclean(entry);

		set_pte_at(mm, address, pte, entry);

			set_pte_at(vma->vm_mm, address, pte, entry);

			ret = 1;

	}

		} else {

#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE

			pmd_t *pmd = pvmw.pmd;

			pmd_t entry;



	pte_unmap_unlock(pte, ptl);

			if (!pmd_dirty(*pmd) && !pmd_write(*pmd))

				continue;



			flush_cache_page(vma, address, page_to_pfn(page));

			entry = pmdp_huge_clear_flush(vma, address, pmd);

			entry = pmd_wrprotect(entry);

			entry = pmd_mkclean(entry);

			set_pmd_at(vma->vm_mm, address, pmd, entry);

			ret = 1;

#else

			/* unexpected pmd-mapped page? */

			WARN_ON_ONCE(1);

#endif

		}



		if (ret) {

		mmu_notifier_invalidate_page(mm, address);

			mmu_notifier_invalidate_page(vma->vm_mm, address);

			(*cleaned)++;

		}

out:

	}



	return SWAP_AGAIN;

}