+ mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch added to mm-new branch

+ mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/khugepaged: unify pmd folio installation with map_anon_folio_pmd()
has been added to the -mm mm-new branch.  Its filename is
     mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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patches, and acceptance into mm-new is a notification for others take
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------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: mm/khugepaged: unify pmd folio installation with map_anon_folio_pmd()
Date: Wed, 8 Oct 2025 09:54:53 +0000

Currently we install pmd folio with map_anon_folio_pmd() in
__do_huge_pmd_anonymous_page() and do_huge_zero_wp_pmd().  While in
collapse_huge_page(), it is done with identical code except statistics
adjustment.

Unify the process with map_anon_folio_pmd() to install pmd folio.  Split
it to map_anon_folio_pmd_pf() and map_anon_folio_pmd_nopf() to be used in
page fault or not respectively.

No functional change is intended.

Link: https://lkml.kernel.org/r/20251008095453.18772-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Lance Yang <lance.yang@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/huge_mm.h |    7 +++++++
 mm/huge_memory.c        |   14 ++++++++++----
 mm/khugepaged.c         |    9 +--------
 3 files changed, 18 insertions(+), 12 deletions(-)

--- a/include/linux/huge_mm.h~mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd
+++ a/include/linux/huge_mm.h
@@ -551,6 +551,8 @@ void split_huge_pmd_locked(struct vm_are
 			   pmd_t *pmd, bool freeze);
 bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,
 			   pmd_t *pmdp, struct folio *folio);
+void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
+		struct vm_area_struct *vma, unsigned long haddr);
 
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 
@@ -642,6 +644,11 @@ static inline bool unmap_huge_pmd_locked
 	return false;
 }
 
+static inline void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
+		struct vm_area_struct *vma, unsigned long haddr)
+{
+}
+
 #define split_huge_pud(__vma, __pmd, __address)	\
 	do { } while (0)
 
--- a/mm/huge_memory.c~mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd
+++ a/mm/huge_memory.c
@@ -1302,7 +1302,7 @@ static struct folio *vma_alloc_anon_foli
 	return folio;
 }
 
-static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,
+void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,
 		struct vm_area_struct *vma, unsigned long haddr)
 {
 	pmd_t entry;
@@ -1313,11 +1313,17 @@ static void map_anon_folio_pmd(struct fo
 	folio_add_lru_vma(folio, vma);
 	set_pmd_at(vma->vm_mm, haddr, pmd, entry);
 	update_mmu_cache_pmd(vma, haddr, pmd);
+	deferred_split_folio(folio, false);
+}
+
+static void map_anon_folio_pmd_pf(struct folio *folio, pmd_t *pmd,
+		struct vm_area_struct *vma, unsigned long haddr)
+{
+	map_anon_folio_pmd_nopf(folio, pmd, vma, haddr);
 	add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
 	count_vm_event(THP_FAULT_ALLOC);
 	count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);
 	count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);
-	deferred_split_folio(folio, false);
 }
 
 static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf)
@@ -1356,7 +1362,7 @@ static vm_fault_t __do_huge_pmd_anonymou
 			return ret;
 		}
 		pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);
-		map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);
+		map_anon_folio_pmd_pf(folio, vmf->pmd, vma, haddr);
 		mm_inc_nr_ptes(vma->vm_mm);
 		spin_unlock(vmf->ptl);
 	}
@@ -2028,7 +2034,7 @@ static vm_fault_t do_huge_zero_wp_pmd(st
 	if (ret)
 		goto release;
 	(void)pmdp_huge_clear_flush(vma, haddr, vmf->pmd);
-	map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);
+	map_anon_folio_pmd_pf(folio, vmf->pmd, vma, haddr);
 	goto unlock;
 release:
 	folio_put(folio);
--- a/mm/khugepaged.c~mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd
+++ a/mm/khugepaged.c
@@ -1311,17 +1311,10 @@ static int collapse_huge_page(struct mm_
 	__folio_mark_uptodate(folio);
 	pgtable = pmd_pgtable(_pmd);
 
-	_pmd = folio_mk_pmd(folio, vma->vm_page_prot);
-	_pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
-
 	spin_lock(pmd_ptl);
 	BUG_ON(!pmd_none(*pmd));
-	folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE);
-	folio_add_lru_vma(folio, vma);
 	pgtable_trans_huge_deposit(mm, pmd, pgtable);
-	set_pmd_at(mm, address, pmd, _pmd);
-	update_mmu_cache_pmd(vma, address, pmd);
-	deferred_split_folio(folio, false);
+	map_anon_folio_pmd_nopf(folio, pmd, vma, address);
 	spin_unlock(pmd_ptl);
 
 	folio = NULL;
_

Patches currently in -mm which might be from richard.weiyang@gmail.com are

mm-compaction-check-the-range-to-pageblock_pfn_to_page-is-within-the-zone-first.patch
mm-compaction-fix-the-range-to-pageblock_pfn_to_page.patch
mm-huge_memory-add-pmd-folio-to-ds_queue-in-do_huge_zero_wp_pmd.patch
mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch