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Subject[PATCH v3 1/6] mm/huge_memory.c: rework the function vma_adjust_trans_huge()
Date
The current implementation of vma_adjust_trans_huge() contains some
duplicated codes. Add helper function to get rid of these codes to make
it more succinct.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/huge_memory.c | 44 +++++++++++++++++++-------------------------
1 file changed, 19 insertions(+), 25 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index bff92dea5ab3..ae16a82da823 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2301,44 +2301,38 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
__split_huge_pmd(vma, pmd, address, freeze, page);
}

+static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address)
+{
+ /*
+ * If the new address isn't hpage aligned and it could previously
+ * contain an hugepage: check if we need to split an huge pmd.
+ */
+ if (!IS_ALIGNED(address, HPAGE_PMD_SIZE) &&
+ range_in_vma(vma, ALIGN_DOWN(address, HPAGE_PMD_SIZE),
+ ALIGN(address, HPAGE_PMD_SIZE)))
+ split_huge_pmd_address(vma, address, false, NULL);
+}
+
void vma_adjust_trans_huge(struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
long adjust_next)
{
- /*
- * If the new start address isn't hpage aligned and it could
- * previously contain an hugepage: check if we need to split
- * an huge pmd.
- */
- if (start & ~HPAGE_PMD_MASK &&
- (start & HPAGE_PMD_MASK) >= vma->vm_start &&
- (start & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end)
- split_huge_pmd_address(vma, start, false, NULL);
+ /* Check if we need to split start first. */
+ split_huge_pmd_if_needed(vma, start);

- /*
- * If the new end address isn't hpage aligned and it could
- * previously contain an hugepage: check if we need to split
- * an huge pmd.
- */
- if (end & ~HPAGE_PMD_MASK &&
- (end & HPAGE_PMD_MASK) >= vma->vm_start &&
- (end & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= vma->vm_end)
- split_huge_pmd_address(vma, end, false, NULL);
+ /* Check if we need to split end next. */
+ split_huge_pmd_if_needed(vma, end);

/*
- * If we're also updating the vma->vm_next->vm_start, if the new
- * vm_next->vm_start isn't hpage aligned and it could previously
- * contain an hugepage: check if we need to split an huge pmd.
+ * If we're also updating the vma->vm_next->vm_start,
+ * check if we need to split it.
*/
if (adjust_next > 0) {
struct vm_area_struct *next = vma->vm_next;
unsigned long nstart = next->vm_start;
nstart += adjust_next;
- if (nstart & ~HPAGE_PMD_MASK &&
- (nstart & HPAGE_PMD_MASK) >= next->vm_start &&
- (nstart & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE <= next->vm_end)
- split_huge_pmd_address(next, nstart, false, NULL);
+ split_huge_pmd_if_needed(next, nstart);
}
}

--
2.19.1
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