From e5251fd43007f9e1155331f0fa30685604a8e3a1 Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Thu, 6 Jul 2017 15:39:50 -0700 Subject: mm/hugetlb: introduce set_huge_swap_pte_at() helper set_huge_pte_at(), an architecture callback to populate hugepage ptes, does not provide the range of virtual memory that is targeted. This leads to ambiguity when dealing with swap entries on architectures that support hugepages consisting of contiguous ptes. Fix the problem by introducing an overridable helper that is called when populating the page tables with swap entries. The size of the targeted region is provided to the helper to help determine the number of entries to be updated. Provide a default implementation that maintains the current behaviour. [punit.agrawal@arm.com: v4] Link: http://lkml.kernel.org/r/20170524115409.31309-8-punit.agrawal@arm.com [punit.agrawal@arm.com: add an empty definition for set_huge_swap_pte_at()] Link: http://lkml.kernel.org/r/20170525171331.31469-1-punit.agrawal@arm.com Link: http://lkml.kernel.org/r/20170522133604.11392-6-punit.agrawal@arm.com Signed-off-by: Punit Agrawal Acked-by: Steve Capper Cc: Mike Kravetz Cc: "Aneesh Kumar K.V" Cc: Catalin Marinas Cc: Will Deacon Cc: Naoya Horiguchi Cc: "Kirill A. Shutemov" Cc: Mark Rutland Cc: Hillf Danton Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3dbe3e257975..51d31352a5bf 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3276,9 +3276,10 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, */ make_migration_entry_read(&swp_entry); entry = swp_entry_to_pte(swp_entry); - set_huge_pte_at(src, addr, src_pte, entry); + set_huge_swap_pte_at(src, addr, src_pte, + entry, sz); } - set_huge_pte_at(dst, addr, dst_pte, entry); + set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); } else { if (cow) { huge_ptep_set_wrprotect(src, addr, src_pte); @@ -4295,7 +4296,8 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma, make_migration_entry_read(&entry); newpte = swp_entry_to_pte(entry); - set_huge_pte_at(mm, address, ptep, newpte); + set_huge_swap_pte_at(mm, address, ptep, + newpte, huge_page_size(h)); pages++; } spin_unlock(ptl); -- cgit v1.2.3