linux-kernel - [PATCH 1/6] mm/huge_memory.c: rework the function vma_adjust_trans

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Date:   Sat, 13 Mar 2021 05:32:19 -0500
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <ziy@...dia.com>, <willy@...radead.org>,
        <william.kucharski@...cle.com>, <vbabka@...e.cz>,
        <richard.weiyang@...ux.alibaba.com>, <peterx@...hat.com>,
        <anshuman.khandual@....com>, <thomas_os@...pmail.org>,
        <rcampbell@...dia.com>, <aneesh.kumar@...ux.ibm.com>,
        <yang.shi@...ux.alibaba.com>, <linux-kernel@...r.kernel.org>,
        <linux-mm@...ck.org>, <linmiaohe@...wei.com>
Subject: [PATCH 1/6] mm/huge_memory.c: rework the function vma_adjust_trans_huge()

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@...wei.com>
---
 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