+ mm-convert-do_set_pmd-to-take-a-folio.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: convert do_set_pmd() to take a folio
has been added to the -mm mm-new branch.  Its filename is
     mm-convert-do_set_pmd-to-take-a-folio.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-convert-do_set_pmd-to-take-a-folio.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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------------------------------------------------------
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Subject: mm: convert do_set_pmd() to take a folio
Date: Mon, 12 May 2025 10:57:12 +0800

In do_set_pmd(), we always use the folio->page to build PMD mappings for
the entire folio.  Since all callers of do_set_pmd() already hold a stable
folio, converting do_set_pmd() to take a folio is safe and more
straightforward.

In addition, to ensure the extensibility of do_set_pmd() for supporting
larger folios beyond PMD size, we keep the 'page' parameter to specify
which page within the folio should be mapped.

No functional changes expected.

Link: https://lkml.kernel.org/r/9b488f4ecb4d3fd8634e3d448dd0ed6964482480.1747017104.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mm.h |    2 +-
 mm/filemap.c       |    2 +-
 mm/khugepaged.c    |    2 +-
 mm/memory.c        |   11 +++++------
 4 files changed, 8 insertions(+), 9 deletions(-)

--- a/include/linux/mm.h~mm-convert-do_set_pmd-to-take-a-folio
+++ a/include/linux/mm.h
@@ -1235,7 +1235,7 @@ static inline pte_t maybe_mkwrite(pte_t
 	return pte;
 }
 
-vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
+vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *page);
 void set_pte_range(struct vm_fault *vmf, struct folio *folio,
 		struct page *page, unsigned int nr, unsigned long addr);
 
--- a/mm/filemap.c~mm-convert-do_set_pmd-to-take-a-folio
+++ a/mm/filemap.c
@@ -3533,7 +3533,7 @@ static bool filemap_map_pmd(struct vm_fa
 
 	if (pmd_none(*vmf->pmd) && folio_test_pmd_mappable(folio)) {
 		struct page *page = folio_file_page(folio, start);
-		vm_fault_t ret = do_set_pmd(vmf, page);
+		vm_fault_t ret = do_set_pmd(vmf, folio, page);
 		if (!ret) {
 			/* The page is mapped successfully, reference consumed. */
 			folio_unlock(folio);
--- a/mm/khugepaged.c~mm-convert-do_set_pmd-to-take-a-folio
+++ a/mm/khugepaged.c
@@ -1478,7 +1478,7 @@ static int set_huge_pmd(struct vm_area_s
 
 	mmap_assert_locked(vma->vm_mm);
 
-	if (do_set_pmd(&vmf, page))
+	if (do_set_pmd(&vmf, folio, page))
 		return SCAN_FAIL;
 
 	folio_get(folio);
--- a/mm/memory.c~mm-convert-do_set_pmd-to-take-a-folio
+++ a/mm/memory.c
@@ -5227,9 +5227,8 @@ static void deposit_prealloc_pte(struct
 	vmf->prealloc_pte = NULL;
 }
 
-vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
+vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *page)
 {
-	struct folio *folio = page_folio(page);
 	struct vm_area_struct *vma = vmf->vma;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
@@ -5302,7 +5301,7 @@ out:
 	return ret;
 }
 #else
-vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
+vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *page)
 {
 	return VM_FAULT_FALLBACK;
 }
@@ -5396,6 +5395,7 @@ fallback:
 	else
 		page = vmf->page;
 
+	folio = page_folio(page);
 	/*
 	 * check even for read faults because we might have lost our CoWed
 	 * page
@@ -5407,8 +5407,8 @@ fallback:
 	}
 
 	if (pmd_none(*vmf->pmd)) {
-		if (PageTransCompound(page)) {
-			ret = do_set_pmd(vmf, page);
+		if (folio_test_pmd_mappable(folio)) {
+			ret = do_set_pmd(vmf, folio, page);
 			if (ret != VM_FAULT_FALLBACK)
 				return ret;
 		}
@@ -5419,7 +5419,6 @@ fallback:
 			return VM_FAULT_OOM;
 	}
 
-	folio = page_folio(page);
 	nr_pages = folio_nr_pages(folio);
 
 	/*
_

Patches currently in -mm which might be from baolin.wang@linux.alibaba.com are

mm-mincore-use-pte_batch_bint-to-batch-process-large-folios.patch
mm-khugepaged-convert-set_huge_pmd-to-take-a-folio.patch
mm-convert-do_set_pmd-to-take-a-folio.patch