linux-kernel - [RFC PATCH 3/3] mm/mremap: Use can_pte_batch_count() instead of folio_pte

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Message-ID: <20251027140315.907864-4-zhangqilong3@huawei.com>
Date: Mon, 27 Oct 2025 22:03:15 +0800
From: Zhang Qilong <zhangqilong3@...wei.com>
To: <akpm@...ux-foundation.org>, <david@...hat.com>,
	<lorenzo.stoakes@...cle.com>, <Liam.Howlett@...cle.com>, <vbabka@...e.cz>,
	<rppt@...nel.org>, <surenb@...gle.com>, <mhocko@...e.com>,
	<jannh@...gle.com>, <pfalcato@...e.de>
CC: <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
	<wangkefeng.wang@...wei.com>, <sunnanyong@...wei.com>
Subject: [RFC PATCH 3/3] mm/mremap: Use can_pte_batch_count() instead of folio_pte_batch() for pte batch

In current mremap_folio_pte_batch(), 1) pte_batch_hint() always
return one pte in non-ARM64 machine, it is not efficient. 2) Next,
it need to acquire a folio to call the folio_pte_batch().

Due to new added can_pte_batch_count(), we just call it instead of
folio_pte_batch(). And then rename mremap_folio_pte_batch() to
mremap_pte_batch().

Signed-off-by: Zhang Qilong <zhangqilong3@...wei.com>
---
 mm/mremap.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/mm/mremap.c b/mm/mremap.c
index bd7314898ec5..d11f93f1622f 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -169,27 +169,17 @@ static pte_t move_soft_dirty_pte(pte_t pte)
 		pte = pte_swp_mksoft_dirty(pte);
 #endif
 	return pte;
 }
 
-static int mremap_folio_pte_batch(struct vm_area_struct *vma, unsigned long addr,
+static int mremap_pte_batch(struct vm_area_struct *vma, unsigned long addr,
 		pte_t *ptep, pte_t pte, int max_nr)
 {
-	struct folio *folio;
-
 	if (max_nr == 1)
 		return 1;
 
-	/* Avoid expensive folio lookup if we stand no chance of benefit. */
-	if (pte_batch_hint(ptep, pte) == 1)
-		return 1;
-
-	folio = vm_normal_folio(vma, addr, pte);
-	if (!folio || !folio_test_large(folio))
-		return 1;
-
-	return folio_pte_batch(folio, ptep, pte, max_nr);
+	return can_pte_batch_count(vma, ptep, &pte, max_nr, 0);
 }
 
 static int move_ptes(struct pagetable_move_control *pmc,
 		unsigned long extent, pmd_t *old_pmd, pmd_t *new_pmd)
 {
@@ -278,11 +268,11 @@ static int move_ptes(struct pagetable_move_control *pmc,
 		 * make sure the physical page stays valid until
 		 * the TLB entry for the old mapping has been
 		 * flushed.
 		 */
 		if (pte_present(old_pte)) {
-			nr_ptes = mremap_folio_pte_batch(vma, old_addr, old_ptep,
+			nr_ptes = mremap_pte_batch(vma, old_addr, old_ptep,
 							 old_pte, max_nr_ptes);
 			force_flush = true;
 		}
 		pte = get_and_clear_ptes(mm, old_addr, old_ptep, nr_ptes);
 		pte = move_pte(pte, old_addr, new_addr);
-- 
2.43.0