Commit 5fd27b8e authored Jul 06, 2017 by Punit Agrawal Committed by Linus Torvalds Jul 06, 2017

mm: rmap: use correct helper when poisoning hugepages

Using set_pte_at() does not do the right thing when putting down
HWPOISON swap entries for hugepages on architectures that support
contiguous ptes.

Fix this problem by using set_huge_swap_pte_at() which was introduced to
fix exactly this problem.

Link: http://lkml.kernel.org/r/20170522133604.11392-7-punit.agrawal@arm.com


Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Steve Capper <steve.capper@arm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e5251fd4

mm/rmap.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -1367,15 +1367,18 @@ static bool try_to_unmap_one(struct page page, struct vm_area_struct vma,
		update_hiwater_rss(mm);

		if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
		pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
		if (PageHuge(page)) {
		int nr = 1 << compound_order(page);
		hugetlb_count_sub(nr, mm);
		set_huge_swap_pte_at(mm, address,
		pvmw.pte, pteval,
		vma_mmu_pagesize(vma));
		} else {
		dec_mm_counter(mm, mm_counter(page));
		set_pte_at(mm, address, pvmw.pte, pteval);
		}

		pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
		set_pte_at(mm, address, pvmw.pte, pteval);
		} else if (pte_unused(pteval)) {
		/*
		* The guest indicated that the page content is of no

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