Message-ID: <20250811112631.759341-1-david@redhat.com>
Date: Mon, 11 Aug 2025 13:26:20 +0200
From: David Hildenbrand <david@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: linux-mm@...ck.org,
	xen-devel@...ts.xenproject.org,
	linux-fsdevel@...r.kernel.org,
	nvdimm@...ts.linux.dev,
	linuxppc-dev@...ts.ozlabs.org,
	David Hildenbrand <david@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Madhavan Srinivasan <maddy@...ux.ibm.com>,
	Michael Ellerman <mpe@...erman.id.au>,
	Nicholas Piggin <npiggin@...il.com>,
	Christophe Leroy <christophe.leroy@...roup.eu>,
	Juergen Gross <jgross@...e.com>,
	Stefano Stabellini <sstabellini@...nel.org>,
	Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
	Dan Williams <dan.j.williams@...el.com>,
	Matthew Wilcox <willy@...radead.org>,
	Jan Kara <jack@...e.cz>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>,
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
	"Liam R. Howlett" <Liam.Howlett@...cle.com>,
	Vlastimil Babka <vbabka@...e.cz>,
	Mike Rapoport <rppt@...nel.org>,
	Suren Baghdasaryan <surenb@...gle.com>,
	Michal Hocko <mhocko@...e.com>,
	Zi Yan <ziy@...dia.com>,
	Baolin Wang <baolin.wang@...ux.alibaba.com>,
	Nico Pache <npache@...hat.com>,
	Ryan Roberts <ryan.roberts@....com>,
	Dev Jain <dev.jain@....com>,
	Barry Song <baohua@...nel.org>,
	Jann Horn <jannh@...gle.com>,
	Pedro Falcato <pfalcato@...e.de>,
	Hugh Dickins <hughd@...gle.com>,
	Oscar Salvador <osalvador@...e.de>,
	Lance Yang <lance.yang@...ux.dev>
Subject: [PATCH v3 00/11] mm: vm_normal_page*() improvements

Based on mm/mm-new from today.

Cleanup and unify vm_normal_page_*() handling, also marking the
huge zerofolio as special in the PMD. Add+use vm_normal_page_pud() and
cleanup that XEN vm_ops->find_special_page thingy.

There are plans of using vm_normal_page_*() more widely soon.

Briefly tested on UML (making sure vm_normal_page() still works as expected
without pte_special() support) and on x86-64 with a bunch of tests.
Cross-compiled for a variety of weird archs.

v2 -> v3:
* "mm/huge_memory: mark PMD mappings of the huge zero folio special"
 -> Extend vm_normal_page_pmd() comment + patch description
 -> Take care of copy_huge_pmd() checking for pmd_special().
* "powerpc/ptdump: rename "struct pgtable_level" to "struct ptdump_pglevel""
 -> Added
* "mm/rmap: convert "enum rmap_level" to "enum pgtable_level""
 -> Added
* "mm/memory: convert print_bad_pte() to print_bad_page_map()"
 -> Consume level so we can keep the level indication through
    pgtable_level_to_str().
 -> Improve locking comments
* "mm/memory: factor out common code from vm_normal_page_*()"
 -> Factor everything out into __vm_normal_page() and let it consume the
    special bit + pfn (and the value+level for error reporting purposes)
 -> Improve function docs
 -> Improve patch description

v1 -> v2:
* "mm/memory: convert print_bad_pte() to print_bad_page_map()"
 -> Don't use pgdp_get(), because it's broken on some arm configs
 -> Extend patch description
 -> Don't use pmd_val(pmdp_get()), because that doesn't work on some
    m68k configs
* Added RBs

RFC -> v1:
* Dropped the highest_memmap_pfn removal stuff and instead added
  "mm/memory: convert print_bad_pte() to print_bad_page_map()"
* Dropped "mm: compare pfns only if the entry is present when inserting
  pfns/pages" for now, will probably clean that up separately.
* Dropped "mm: remove "horrible special case to handle copy-on-write
  behaviour"", and "mm: drop addr parameter from vm_normal_*_pmd()" will
  require more thought
* "mm/huge_memory: support huge zero folio in vmf_insert_folio_pmd()"
 -> Extend patch description.
* "fs/dax: use vmf_insert_folio_pmd() to insert the huge zero folio"
 -> Extend patch description.
* "mm/huge_memory: mark PMD mappings of the huge zero folio special"
 -> Remove comment from vm_normal_page_pmd().
* "mm/memory: factor out common code from vm_normal_page_*()"
 -> Adjust to print_bad_page_map()/highest_memmap_pfn changes.
 -> Add proper kernel doc to all involved functions
* "mm: introduce and use vm_normal_page_pud()"
 -> Adjust to print_bad_page_map() changes.

Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Madhavan Srinivasan <maddy@...ux.ibm.com>
Cc: Michael Ellerman <mpe@...erman.id.au>
Cc: Nicholas Piggin <npiggin@...il.com>
Cc: Christophe Leroy <christophe.leroy@...roup.eu>
Cc: Juergen Gross <jgross@...e.com>
Cc: Stefano Stabellini <sstabellini@...nel.org>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>
Cc: Dan Williams <dan.j.williams@...el.com>
Cc: Matthew Wilcox <willy@...radead.org>
Cc: Jan Kara <jack@...e.cz>
Cc: Alexander Viro <viro@...iv.linux.org.uk>
Cc: Christian Brauner <brauner@...nel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Cc: "Liam R. Howlett" <Liam.Howlett@...cle.com>
Cc: Vlastimil Babka <vbabka@...e.cz>
Cc: Mike Rapoport <rppt@...nel.org>
Cc: Suren Baghdasaryan <surenb@...gle.com>
Cc: Michal Hocko <mhocko@...e.com>
Cc: Zi Yan <ziy@...dia.com>
Cc: Baolin Wang <baolin.wang@...ux.alibaba.com>
Cc: Nico Pache <npache@...hat.com>
Cc: Ryan Roberts <ryan.roberts@....com>
Cc: Dev Jain <dev.jain@....com>
Cc: Barry Song <baohua@...nel.org>
Cc: Jann Horn <jannh@...gle.com>
Cc: Pedro Falcato <pfalcato@...e.de>
Cc: Hugh Dickins <hughd@...gle.com>
Cc: Oscar Salvador <osalvador@...e.de>
Cc: Lance Yang <lance.yang@...ux.dev>

David Hildenbrand (11):
  mm/huge_memory: move more common code into insert_pmd()
  mm/huge_memory: move more common code into insert_pud()
  mm/huge_memory: support huge zero folio in vmf_insert_folio_pmd()
  fs/dax: use vmf_insert_folio_pmd() to insert the huge zero folio
  mm/huge_memory: mark PMD mappings of the huge zero folio special
  powerpc/ptdump: rename "struct pgtable_level" to "struct
    ptdump_pglevel"
  mm/rmap: convert "enum rmap_level" to "enum pgtable_level"
  mm/memory: convert print_bad_pte() to print_bad_page_map()
  mm/memory: factor out common code from vm_normal_page_*()
  mm: introduce and use vm_normal_page_pud()
  mm: rename vm_ops->find_special_page() to vm_ops->find_normal_page()

 arch/powerpc/mm/ptdump/8xx.c      |   2 +-
 arch/powerpc/mm/ptdump/book3s64.c |   2 +-
 arch/powerpc/mm/ptdump/ptdump.h   |   4 +-
 arch/powerpc/mm/ptdump/shared.c   |   2 +-
 drivers/xen/Kconfig               |   1 +
 drivers/xen/gntdev.c              |   5 +-
 fs/dax.c                          |  47 +----
 include/linux/mm.h                |  20 +-
 include/linux/pgtable.h           |  27 +++
 include/linux/rmap.h              |  60 +++---
 mm/Kconfig                        |   2 +
 mm/huge_memory.c                  | 122 +++++------
 mm/memory.c                       | 332 +++++++++++++++++++++---------
 mm/pagewalk.c                     |  20 +-
 mm/rmap.c                         |  56 ++---
 tools/testing/vma/vma_internal.h  |  18 +-
 16 files changed, 421 insertions(+), 299 deletions(-)


base-commit: 53c448023185717d0ed56b5546dc2be405da92ff
-- 
2.50.1

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