The patch titled
Subject: mm: make page_mapped() take a const argument
has been added to the -mm mm-unstable branch. Its filename is
mm-make-page_mapped-take-a-const-argument.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-make-page_mapped-take-a-const-argument.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: mm: make page_mapped() take a const argument
Date: Tue, 26 Mar 2024 17:10:28 +0000
None of the functions called by page_mapped() modify the page or folio, so
mark them all as const.
Link: https://lkml.kernel.org/r/20240326171045.410737-7-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 12 ++++++------
mm/internal.h | 7 ++++---
mm/rmap.c | 2 +-
3 files changed, 11 insertions(+), 10 deletions(-)
--- a/include/linux/mm.h~mm-make-page_mapped-take-a-const-argument
+++ a/include/linux/mm.h
@@ -1200,7 +1200,7 @@ static inline int is_vmalloc_or_module_a
* debugging purposes - it does not include PTE-mapped sub-pages; look
* at folio_mapcount() or page_mapcount() instead.
*/
-static inline int folio_entire_mapcount(struct folio *folio)
+static inline int folio_entire_mapcount(const struct folio *folio)
{
VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
return atomic_read(&folio->_entire_mapcount) + 1;
@@ -1240,7 +1240,7 @@ static inline int page_mapcount(struct p
return mapcount;
}
-int folio_total_mapcount(struct folio *folio);
+int folio_total_mapcount(const struct folio *folio);
/**
* folio_mapcount() - Calculate the number of mappings of this folio.
@@ -1253,14 +1253,14 @@ int folio_total_mapcount(struct folio *f
*
* Return: The number of times this folio is mapped.
*/
-static inline int folio_mapcount(struct folio *folio)
+static inline int folio_mapcount(const struct folio *folio)
{
if (likely(!folio_test_large(folio)))
return atomic_read(&folio->_mapcount) + 1;
return folio_total_mapcount(folio);
}
-static inline bool folio_large_is_mapped(struct folio *folio)
+static inline bool folio_large_is_mapped(const struct folio *folio)
{
/*
* Reading _entire_mapcount below could be omitted if hugetlb
@@ -1288,7 +1288,7 @@ static inline bool folio_mapped(struct f
* For compound page it returns true if any sub-page of compound page is mapped,
* even if this particular sub-page is not itself mapped by any PTE or PMD.
*/
-static inline bool page_mapped(struct page *page)
+static inline bool page_mapped(const struct page *page)
{
if (likely(!PageCompound(page)))
return atomic_read(&page->_mapcount) >= 0;
@@ -2070,7 +2070,7 @@ static inline void set_page_links(struct
*
* Return: A positive power of two.
*/
-static inline long folio_nr_pages(struct folio *folio)
+static inline long folio_nr_pages(const struct folio *folio)
{
if (!folio_test_large(folio))
return 1;
--- a/mm/internal.h~mm-make-page_mapped-take-a-const-argument
+++ a/mm/internal.h
@@ -71,7 +71,7 @@ void page_writeback_init(void);
* How many individual pages have an elevated _mapcount. Excludes
* the folio's entire_mapcount.
*/
-static inline int folio_nr_pages_mapped(struct folio *folio)
+static inline int folio_nr_pages_mapped(const struct folio *folio)
{
return atomic_read(&folio->_nr_pages_mapped) & FOLIO_PAGES_MAPPED;
}
@@ -81,7 +81,8 @@ static inline int folio_nr_pages_mapped(
* folio. We cannot rely on folio->swap as there is no guarantee that it has
* been initialized. Used for calling arch_swap_restore()
*/
-static inline swp_entry_t folio_swap(swp_entry_t entry, struct folio *folio)
+static inline swp_entry_t folio_swap(swp_entry_t entry,
+ const struct folio *folio)
{
swp_entry_t swap = {
.val = ALIGN_DOWN(entry.val, folio_nr_pages(folio)),
@@ -90,7 +91,7 @@ static inline swp_entry_t folio_swap(swp
return swap;
}
-static inline void *folio_raw_mapping(struct folio *folio)
+static inline void *folio_raw_mapping(const struct folio *folio)
{
unsigned long mapping = (unsigned long)folio->mapping;
--- a/mm/rmap.c~mm-make-page_mapped-take-a-const-argument
+++ a/mm/rmap.c
@@ -1134,7 +1134,7 @@ int pfn_mkclean_range(unsigned long pfn,
return page_vma_mkclean_one(&pvmw);
}
-int folio_total_mapcount(struct folio *folio)
+int folio_total_mapcount(const struct folio *folio)
{
int mapcount = folio_entire_mapcount(folio);
int nr_pages;
_
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
