[PATCH 3.2 32/46] thp: introduce hugepage_vma_check()

Ben Hutchings
2016-06-12T21:34:42Z

From: Bob Liu <lliubbo@gmail.com>

commit fa475e517adb422cb3492e636195f9b2c0d009c8 upstream.

Multiple places do the same check.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Ni zhan Chen <nizhan.chen@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2:
- Also move the is_linear_pfn_mapping() test
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
mm/huge_memory.c | 38 +++++++++++++++++---------------------
1 file changed, 17 insertions(+), 21 deletions(-)

--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1817,6 +1817,24 @@ static void __collapse_huge_page_copy(pt
}
}

+static bool hugepage_vma_check(struct vm_area_struct *vma)
+{
+ if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE))
+ return false;
+
+ if (!vma->anon_vma || vma->vm_ops)
+ return false;
+ if (is_vma_temporary_stack(vma))
+ return false;
+ /*
+ * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
+ * true too, verify it here.
+ */
+ VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
+ return true;
+}
+
static void collapse_huge_page(struct mm_struct *mm,
unsigned long address,
struct page **hpage,
@@ -1889,21 +1907,8 @@ static void collapse_huge_page(struct mm
hend = vma->vm_end & HPAGE_PMD_MASK;
if (address < hstart || address + HPAGE_PMD_SIZE > hend)
goto out;
-
- if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
- (vma->vm_flags & VM_NOHUGEPAGE))
+ if (!hugepage_vma_check(vma))
goto out;
-
- if (!vma->anon_vma || vma->vm_ops)
- goto out;
- if (is_vma_temporary_stack(vma))
- goto out;
- /*
- * If is_pfn_mapping() is true is_learn_pfn_mapping() must be
- * true too, verify it here.
- */
- VM_BUG_ON(is_linear_pfn_mapping(vma) || vma->vm_flags & VM_NO_THP);
-
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
goto out;
@@ -2133,25 +2138,11 @@ static unsigned int khugepaged_scan_mm_s
progress++;
break;
}
-
- if ((!(vma->vm_flags & VM_HUGEPAGE) &&
- !khugepaged_always()) ||
- (vma->vm_flags & VM_NOHUGEPAGE)) {
- skip:
+ if (!hugepage_vma_check(vma)) {
+skip:
progress++;
continue;
}
- if (!vma->anon_vma || vma->vm_ops)
- goto skip;
- if (is_vma_temporary_stack(vma))
- goto skip;
- /*
- * If is_pfn_mapping() is true is_learn_pfn_mapping()
- * must be true too, verify it here.
- */
- VM_BUG_ON(is_linear_pfn_mapping(vma) ||
- vma->vm_flags & VM_NO_THP);
-
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
hend = vma->vm_end & HPAGE_PMD_MASK;
if (hstart >= hend)