[PATCH v3 1/6] mm/huge_memory.c: rework the function vma_adjust_trans_huge()

[Miaohe Lin]

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 <linmia...@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