diff options
Diffstat (limited to 'mm/swapfile.c')
-rw-r--r-- | mm/swapfile.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 36af6eeaa67e..6cf2e60983b7 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c | |||
@@ -866,6 +866,21 @@ unsigned int count_swap_pages(int type, int free) | |||
866 | } | 866 | } |
867 | #endif /* CONFIG_HIBERNATION */ | 867 | #endif /* CONFIG_HIBERNATION */ |
868 | 868 | ||
869 | static inline int maybe_same_pte(pte_t pte, pte_t swp_pte) | ||
870 | { | ||
871 | #ifdef CONFIG_MEM_SOFT_DIRTY | ||
872 | /* | ||
873 | * When pte keeps soft dirty bit the pte generated | ||
874 | * from swap entry does not has it, still it's same | ||
875 | * pte from logical point of view. | ||
876 | */ | ||
877 | pte_t swp_pte_dirty = pte_swp_mksoft_dirty(swp_pte); | ||
878 | return pte_same(pte, swp_pte) || pte_same(pte, swp_pte_dirty); | ||
879 | #else | ||
880 | return pte_same(pte, swp_pte); | ||
881 | #endif | ||
882 | } | ||
883 | |||
869 | /* | 884 | /* |
870 | * No need to decide whether this PTE shares the swap entry with others, | 885 | * No need to decide whether this PTE shares the swap entry with others, |
871 | * just let do_wp_page work it out if a write is requested later - to | 886 | * just let do_wp_page work it out if a write is requested later - to |
@@ -892,7 +907,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, | |||
892 | } | 907 | } |
893 | 908 | ||
894 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | 909 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
895 | if (unlikely(!pte_same(*pte, swp_entry_to_pte(entry)))) { | 910 | if (unlikely(!maybe_same_pte(*pte, swp_entry_to_pte(entry)))) { |
896 | mem_cgroup_cancel_charge_swapin(memcg); | 911 | mem_cgroup_cancel_charge_swapin(memcg); |
897 | ret = 0; | 912 | ret = 0; |
898 | goto out; | 913 | goto out; |
@@ -947,7 +962,7 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, | |||
947 | * swapoff spends a _lot_ of time in this loop! | 962 | * swapoff spends a _lot_ of time in this loop! |
948 | * Test inline before going to call unuse_pte. | 963 | * Test inline before going to call unuse_pte. |
949 | */ | 964 | */ |
950 | if (unlikely(pte_same(*pte, swp_pte))) { | 965 | if (unlikely(maybe_same_pte(*pte, swp_pte))) { |
951 | pte_unmap(pte); | 966 | pte_unmap(pte); |
952 | ret = unuse_pte(vma, pmd, addr, entry, page); | 967 | ret = unuse_pte(vma, pmd, addr, entry, page); |
953 | if (ret) | 968 | if (ret) |