linux-kernel - [PATCH v3 05/16] mm/huge_memory: use helper touch_pmd in huge_pmd_set

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Date:   Mon, 4 Jul 2022 21:21:50 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <shy828301@...il.com>, <willy@...radead.org>, <zokeefe@...gle.com>,
        <songmuchun@...edance.com>, <linux-mm@...ck.org>,
        <linux-kernel@...r.kernel.org>, <linmiaohe@...wei.com>
Subject: [PATCH v3 05/16] mm/huge_memory: use helper touch_pmd in huge_pmd_set_accessed

Use helper touch_pmd to set pmd accessed to simplify the code and improve
the readability. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 mm/huge_memory.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 30acb3b994cf..f9b6eb3f2215 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1121,15 +1121,15 @@ EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud_prot);
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 
 static void touch_pmd(struct vm_area_struct *vma, unsigned long addr,
-		pmd_t *pmd, int flags)
+		      pmd_t *pmd, bool write)
 {
 	pmd_t _pmd;
 
 	_pmd = pmd_mkyoung(*pmd);
-	if (flags & FOLL_WRITE)
+	if (write)
 		_pmd = pmd_mkdirty(_pmd);
 	if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK,
-				pmd, _pmd, flags & FOLL_WRITE))
+				  pmd, _pmd, write))
 		update_mmu_cache_pmd(vma, addr, pmd);
 }
 
@@ -1162,7 +1162,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 
 	if (flags & FOLL_TOUCH)
-		touch_pmd(vma, addr, pmd, flags);
+		touch_pmd(vma, addr, pmd, flags & FOLL_WRITE);
 
 	/*
 	 * device mapped pages can only be returned if the
@@ -1399,21 +1399,13 @@ void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
 
 void huge_pmd_set_accessed(struct vm_fault *vmf)
 {
-	pmd_t entry;
-	unsigned long haddr;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
-	pmd_t orig_pmd = vmf->orig_pmd;
 
 	vmf->ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd);
-	if (unlikely(!pmd_same(*vmf->pmd, orig_pmd)))
+	if (unlikely(!pmd_same(*vmf->pmd, vmf->orig_pmd)))
 		goto unlock;
 
-	entry = pmd_mkyoung(orig_pmd);
-	if (write)
-		entry = pmd_mkdirty(entry);
-	haddr = vmf->address & HPAGE_PMD_MASK;
-	if (pmdp_set_access_flags(vmf->vma, haddr, vmf->pmd, entry, write))
-		update_mmu_cache_pmd(vmf->vma, vmf->address, vmf->pmd);
+	touch_pmd(vmf->vma, vmf->address, vmf->pmd, write);
 
 unlock:
 	spin_unlock(vmf->ptl);
@@ -1549,7 +1541,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 		return ERR_PTR(-ENOMEM);
 
 	if (flags & FOLL_TOUCH)
-		touch_pmd(vma, addr, pmd, flags);
+		touch_pmd(vma, addr, pmd, flags & FOLL_WRITE);
 
 	page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT;
 	VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page);
-- 
2.23.0