mm/hugetlb: introduce set_huge_swap_pte_at() helper (e5251fd4) · Commits · 戴 / test

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 <punit.agrawal@arm.com> Acked-by:

Steve Capper <steve.capper@arm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.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: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.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>

include/linux/hugetlb.h

+13 −0

Original line number	Diff line number	Diff line
		@@ -516,6 +516,14 @@ static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
		{
		atomic_long_sub(l, &mm->hugetlb_usage);
		}

		#ifndef set_huge_swap_pte_at
		static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
		pte_t *ptep, pte_t pte, unsigned long sz)
		{
		set_huge_pte_at(mm, addr, ptep, pte);
		}
		#endif
		#else /* CONFIG_HUGETLB_PAGE */
		struct hstate {};
		#define alloc_huge_page(v, a, r) NULL
		@@ -565,6 +573,11 @@ static inline void hugetlb_report_usage(struct seq_file f, struct mm_struct m)
		static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
		{
		}

		static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
		pte_t *ptep, pte_t pte, unsigned long sz)
		{
		}
		#endif /* CONFIG_HUGETLB_PAGE */

		static inline spinlock_t huge_pte_lock(struct hstate h,

mm/hugetlb.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -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);

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