The patch titled
Subject: remove references to page->flags in documentation
has been added to the -mm mm-unstable branch. Its filename is
remove-references-to-page-flags-in-documentation.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/remove-references-to-page-flags-in-documentation.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: remove references to page->flags in documentation
Date: Tue, 26 Mar 2024 17:10:31 +0000
Mostly rewording, but remove entirely the copy of page_fixed_fake_head()
in the documentation; we can refer people to the actual source if
necessary.
Link: https://lkml.kernel.org/r/20240326171045.410737-10-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/cgroup-v1/memory.rst | 4 -
Documentation/mm/vmemmap_dedup.rst | 22 ----------
Documentation/translations/zh_CN/core-api/cachetlb.rst | 2
mm/migrate.c | 2
mm/rmap.c | 4 -
5 files changed, 7 insertions(+), 27 deletions(-)
--- a/Documentation/admin-guide/cgroup-v1/memory.rst~remove-references-to-page-flags-in-documentation
+++ a/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -300,14 +300,14 @@ When oom event notifier is registered, e
Lock order is as follows::
- Page lock (PG_locked bit of page->flags)
+ folio_lock
mm->page_table_lock or split pte_lock
folio_memcg_lock (memcg->move_lock)
mapping->i_pages lock
lruvec->lru_lock.
Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by
-lruvec->lru_lock; PG_lru bit of page->flags is cleared before
+lruvec->lru_lock; the folio LRU flag is cleared before
isolating a page from its LRU under lruvec->lru_lock.
.. _cgroup-v1-memory-kernel-extension:
--- a/Documentation/mm/vmemmap_dedup.rst~remove-references-to-page-flags-in-documentation
+++ a/Documentation/mm/vmemmap_dedup.rst
@@ -180,27 +180,7 @@ this correctly. There is only **one** he
``struct page`` with ``PG_head`` are fake head ``struct page``. We need an
approach to distinguish between those two different types of ``struct page`` so
that ``compound_head()`` can return the real head ``struct page`` when the
-parameter is the tail ``struct page`` but with ``PG_head``. The following code
-snippet describes how to distinguish between real and fake head ``struct page``.
-
-.. code-block:: c
-
- if (test_bit(PG_head, &page->flags)) {
- unsigned long head = READ_ONCE(page[1].compound_head);
-
- if (head & 1) {
- if (head == (unsigned long)page + 1)
- /* head struct page */
- else
- /* tail struct page */
- } else {
- /* head struct page */
- }
- }
-
-We can safely access the field of the **page[1]** with ``PG_head`` because the
-page is a compound page composed with at least two contiguous pages.
-The implementation refers to ``page_fixed_fake_head()``.
+parameter is the tail ``struct page`` but with ``PG_head``.
Device DAX
==========
--- a/Documentation/translations/zh_CN/core-api/cachetlb.rst~remove-references-to-page-flags-in-documentation
+++ a/Documentation/translations/zh_CN/core-api/cachetlb.rst
@@ -260,7 +260,7 @@ é?®é¢?æ??å?¯è?½å?å?¨ï¼?å? 为å??æ ¸å·²ç
å¦?æ??D-cacheå?«å??ä¸?æ?¯ä¸?个é?®é¢?ï¼?è¿?个ç¨?åº?å?¯ä»¥ç®?å??å?°å®?ä¹?为该æ?¶æ??ä¸?
ç??nopã??
- å?¨page->flags (PG_arch_1)ä¸æ??ä¸?个ä½?æ?¯â??æ?¶æ??ç§?æ??â??ã??å??æ ¸ä¿?è¯?ï¼?
+ å?¨folio->flags (PG_arch_1)ä¸æ??ä¸?个ä½?æ?¯â??æ?¶æ??ç§?æ??â??ã??å??æ ¸ä¿?è¯?ï¼?
对äº?å??页ç¼?å?ç??页é?¢ï¼?å½?è¿?æ ·ç??页é?¢ç¬¬ä¸?次è¿?å?¥å??页ç¼?å?æ?¶ï¼?å®?å°?æ¸?é?¤
è¿?个ä½?ã??
--- a/mm/migrate.c~remove-references-to-page-flags-in-documentation
+++ a/mm/migrate.c
@@ -113,7 +113,7 @@ bool isolate_movable_page(struct page *p
if (!mops->isolate_page(&folio->page, mode))
goto out_no_isolated;
- /* Driver shouldn't use PG_isolated bit of page->flags */
+ /* Driver shouldn't use the isolated flag */
WARN_ON_ONCE(folio_test_isolated(folio));
folio_set_isolated(folio);
folio_unlock(folio);
--- a/mm/rmap.c~remove-references-to-page-flags-in-documentation
+++ a/mm/rmap.c
@@ -23,7 +23,7 @@
* inode->i_rwsem (while writing or truncating, not reading or faulting)
* mm->mmap_lock
* mapping->invalidate_lock (in filemap_fault)
- * page->flags PG_locked (lock_page)
+ * folio_lock
* hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share, see hugetlbfs below)
* vma_start_write
* mapping->i_mmap_rwsem
@@ -50,7 +50,7 @@
* hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
* vma_lock (hugetlb specific lock for pmd_sharing)
* mapping->i_mmap_rwsem (also used for hugetlb pmd sharing)
- * page->flags PG_locked (lock_page)
+ * folio_lock
*/
#include <linux/mm.h>
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-always-initialise-folio-_deferred_list.patch
mm-create-folio_flag_false-and-folio_type_ops-macros.patch
mm-remove-folio_prep_large_rmappable.patch
mm-support-page_mapcount-on-page_has_type-pages.patch
mm-turn-folio_test_hugetlb-into-a-pagetype.patch
mm-turn-folio_test_hugetlb-into-a-pagetype-fix.patch
mm-remove-a-call-to-compound_head-from-is_page_hwpoison.patch
mm-free-up-pg_slab.patch
mm-free-up-pg_slab-fix.patch
mm-improve-dumping-of-mapcount-and-page_type.patch
hugetlb-remove-mention-of-destructors.patch
sh-remove-use-of-pg_arch_1-on-individual-pages.patch
xtensa-remove-uses-of-pg_arch_1-on-individual-pages.patch
mm-make-page_ext_get-take-a-const-argument.patch
mm-make-folio_test_idle-and-folio_test_young-take-a-const-argument.patch
mm-make-is_free_buddy_page-take-a-const-argument.patch
mm-make-page_mapped-take-a-const-argument.patch
mm-convert-arch_clear_hugepage_flags-to-take-a-folio.patch
slub-remove-use-of-page-flags.patch
remove-references-to-page-flags-in-documentation.patch
proc-rewrite-stable_page_flags.patch
