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Commit 021740dc authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
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[PATCH] freepgt: hugetlb area is clean 



Once we're strict about clearing away page tables, hugetlb_prefault can assume
there are no page tables left within its range.  Since the other arches
continue if !pte_none here, let i386 do the same.

Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 146425a3

arch/i386/mm/hugetlbpage.c

+2 −9
Original line number Diff line number Diff line
@@ -249,15 +249,8 @@ int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma) 
			goto out;

		}



		if (!pte_none(*pte)) {

			pmd_t *pmd = (pmd_t *) pte;



			page = pmd_page(*pmd);

			pmd_clear(pmd);

			mm->nr_ptes--;

			dec_page_state(nr_page_table_pages);

			page_cache_release(page);

		}

		if (!pte_none(*pte))

			continue;



		idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)

			+ (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));

arch/ppc64/mm/hugetlbpage.c

+0 −37
Original line number Diff line number Diff line
@@ -203,8 +203,6 @@ static int prepare_low_seg_for_htlb(struct mm_struct *mm, unsigned long seg) 
	unsigned long start = seg << SID_SHIFT;

	unsigned long end = (seg+1) << SID_SHIFT;

	struct vm_area_struct *vma;

	unsigned long addr;

	struct mmu_gather *tlb;



	BUG_ON(seg >= 16);
@@ -213,41 +211,6 @@ static int prepare_low_seg_for_htlb(struct mm_struct *mm, unsigned long seg) 
	if (vma && (vma->vm_start < end))

		return -EBUSY;



	/* Clean up any leftover PTE pages in the region */

	spin_lock(&mm->page_table_lock);

	tlb = tlb_gather_mmu(mm, 0);

	for (addr = start; addr < end; addr += PMD_SIZE) {

		pgd_t *pgd = pgd_offset(mm, addr);

		pmd_t *pmd;

		struct page *page;

		pte_t *pte;

		int i;



		if (pgd_none(*pgd))

			continue;

		pmd = pmd_offset(pgd, addr);

		if (!pmd || pmd_none(*pmd))

			continue;

		if (pmd_bad(*pmd)) {

			pmd_ERROR(*pmd);

			pmd_clear(pmd);

			continue;

		}

		pte = (pte_t *)pmd_page_kernel(*pmd);

		/* No VMAs, so there should be no PTEs, check just in case. */

		for (i = 0; i < PTRS_PER_PTE; i++) {

			BUG_ON(!pte_none(*pte));

			pte++;

		}

		page = pmd_page(*pmd);

		pmd_clear(pmd);

		mm->nr_ptes--;

		dec_page_state(nr_page_table_pages);

		pte_free_tlb(tlb, page);

	}

	tlb_finish_mmu(tlb, start, end);

	spin_unlock(&mm->page_table_lock);



	return 0;

}