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

From: Miaohe Lin
Date: Sat Mar 13 2021 - 05:38:56 EST


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@xxxxxxxxxx>
---
mm/huge_memory.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index bff92dea5ab3..3303576489d5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2301,6 +2301,14 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
__split_huge_pmd(vma, pmd, address, freeze, page);
}

+static inline void try_to_split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address)
+{
+ if (address & ~HPAGE_PMD_MASK &&
+ range_in_vma(vma, address & HPAGE_PMD_MASK,
+ (address & HPAGE_PMD_MASK) + 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,
@@ -2311,20 +2319,14 @@ void vma_adjust_trans_huge(struct vm_area_struct *vma,
* 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);
+ try_to_split_huge_pmd_address(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);
+ try_to_split_huge_pmd_address(vma, end);

/*
* If we're also updating the vma->vm_next->vm_start, if the new
@@ -2335,10 +2337,7 @@ void vma_adjust_trans_huge(struct vm_area_struct *vma,
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);
+ try_to_split_huge_pmd_address(next, nstart);
}
}

--
2.19.1