linux-kernel - [PATCH 4/9] mm/damon/vaddr: use vm_normal_folio{,_pmd}() instead of damon_get

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Message-ID: <20251112154114.66053-5-sj@kernel.org>
Date: Wed, 12 Nov 2025 07:41:07 -0800
From: SeongJae Park <sj@...nel.org>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: SeongJae Park <sj@...nel.org>,
	damon@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	David Hildenbrand <david@...nel.org>
Subject: [PATCH 4/9] mm/damon/vaddr: use vm_normal_folio{,_pmd}() instead of damon_get_folio()

A few page table walk entry callback functions in vaddr.c uses
damon_get_folio() with p{te,md}_pfn() to get the folio, and then
put_folio().  Simplify and drop unnecessary folio get/put by using
vm_normal_folio() and its friends instead.

Note that this cleanup was suggested by David Hildenbrand during a
review of another patch series [1] and the patch was updated following
the suggestion.  This patch further applies the cleanup to DAMON code
that merged before the patch.

[1] https://lore.kernel.org/0cb3d5a5-683b-4dba-90a8-b45ab83eec53@redhat.com

Suggested-by: David Hildenbrand <david@...nel.org>
Signed-off-by: SeongJae Park <sj@...nel.org>
---
 mm/damon/vaddr.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 0ad1ce120aa1..9c06cfe4526f 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -442,7 +442,7 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
 
 		if (!pmd_present(pmde))
 			goto huge_out;
-		folio = damon_get_folio(pmd_pfn(pmde));
+		folio = vm_normal_folio_pmd(walk->vma, addr, pmde);
 		if (!folio)
 			goto huge_out;
 		if (pmd_young(pmde) || !folio_test_idle(folio) ||
@@ -450,7 +450,6 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
 						addr))
 			priv->young = true;
 		*priv->folio_sz = HPAGE_PMD_SIZE;
-		folio_put(folio);
 huge_out:
 		spin_unlock(ptl);
 		return 0;
@@ -463,14 +462,13 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
 	ptent = ptep_get(pte);
 	if (!pte_present(ptent))
 		goto out;
-	folio = damon_get_folio(pte_pfn(ptent));
+	folio = vm_normal_folio(walk->vma, addr, ptent);
 	if (!folio)
 		goto out;
 	if (pte_young(ptent) || !folio_test_idle(folio) ||
 			mmu_notifier_test_young(walk->mm, addr))
 		priv->young = true;
 	*priv->folio_sz = folio_size(folio);
-	folio_put(folio);
 out:
 	pte_unmap_unlock(pte, ptl);
 	return 0;
@@ -718,18 +716,16 @@ static int damos_va_migrate_pmd_entry(pmd_t *pmd, unsigned long addr,
 	/* Tell page walk code to not split the PMD */
 	walk->action = ACTION_CONTINUE;
 
-	folio = damon_get_folio(pmd_pfn(pmde));
+	folio = vm_normal_folio_pmd(walk->vma, addr, pmde);
 	if (!folio)
 		goto unlock;
 
 	if (damos_va_filter_out(s, folio, walk->vma, addr, NULL, pmd))
-		goto put_folio;
+		goto unlock;
 
 	damos_va_migrate_dests_add(folio, walk->vma, addr, dests,
 		migration_lists);
 
-put_folio:
-	folio_put(folio);
 unlock:
 	spin_unlock(ptl);
 	return 0;
@@ -752,18 +748,15 @@ static int damos_va_migrate_pte_entry(pte_t *pte, unsigned long addr,
 	if (pte_none(ptent) || !pte_present(ptent))
 		return 0;
 
-	folio = damon_get_folio(pte_pfn(ptent));
+	folio = vm_normal_folio(walk->vma, addr, ptent);
 	if (!folio)
 		return 0;
 
 	if (damos_va_filter_out(s, folio, walk->vma, addr, pte, NULL))
-		goto put_folio;
+		return 0;
 
 	damos_va_migrate_dests_add(folio, walk->vma, addr, dests,
 		migration_lists);
-
-put_folio:
-	folio_put(folio);
 	return 0;
 }
 
-- 
2.47.3