Messages in this thread Patch in this message | | | From | "Kirill A. Shutemov" <> | Subject | [PATCHv3 02/17] mm/khugepaged: Do not collapse pages in encrypted VMAs | Date | Tue, 12 Jun 2018 17:39:00 +0300 |
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Pages for encrypted VMAs have to be allocated in a special way: we would need to propagate down not only desired NUMA node but also whether the page is encrypted.
It complicates not-so-trivial routine of huge page allocation in khugepaged even more. It also puts more pressure on page allocator: we cannot re-use pages allocated for encrypted VMA to collapse page in unencrypted one or vice versa.
I think for now it worth skipping encrypted VMAs. We can return to this topic later.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- include/linux/mm.h | 7 +++++++ mm/khugepaged.c | 2 ++ 2 files changed, 9 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 1c3c15f37ed6..435b053c457c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1492,6 +1492,13 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma) return !vma->vm_ops; } +#ifndef vma_is_encrypted +static inline bool vma_is_encrypted(struct vm_area_struct *vma) +{ + return false; +} +#endif + #ifndef vma_keyid static inline int vma_keyid(struct vm_area_struct *vma) { diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d7b2a4bf8671..a03b40bef033 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -835,6 +835,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma) return false; if (is_vma_temporary_stack(vma)) return false; + if (vma_is_encrypted(vma)) + return false; return !(vma->vm_flags & VM_NO_KHUGEPAGED); } -- 2.17.1
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