Neither of these functions modify their argument; make it const
so the compiler knows this and can optimise accordingly.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/pagemap.h | 4 ++--
mm/debug.c | 2 +-
mm/swapfile.c | 2 +-
mm/util.c | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 47bfc6b1b632..8a9b2d201706 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -532,8 +532,8 @@ static inline void filemap_nr_thps_dec(struct address_space *mapping)
#endif
}
-struct address_space *folio_mapping(struct folio *);
-struct address_space *swapcache_mapping(struct folio *);
+struct address_space *folio_mapping(const struct folio *);
+struct address_space *swapcache_mapping(const struct folio *);
/**
* folio_file_mapping - Find the mapping this folio belongs to.
diff --git a/mm/debug.c b/mm/debug.c
index 8d2acf432385..fa3d9686034c 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -67,7 +67,7 @@ static const char *page_type_name(unsigned int page_type)
return page_type_names[i];
}
-static void __dump_folio(struct folio *folio, struct page *page,
+static void __dump_folio(const struct folio *folio, struct page *page,
unsigned long pfn, unsigned long idx)
{
struct address_space *mapping = folio_mapping(folio);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 6e867c16ea93..ccaed8c2f761 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3658,7 +3658,7 @@ struct swap_info_struct *swp_swap_info(swp_entry_t entry)
/*
* out-of-line methods to avoid include hell.
*/
-struct address_space *swapcache_mapping(struct folio *folio)
+struct address_space *swapcache_mapping(const struct folio *folio)
{
return swp_swap_info(folio->swap)->swap_file->f_mapping;
}
diff --git a/mm/util.c b/mm/util.c
index b6b9684a1438..682ecdb1b1c2 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -845,7 +845,7 @@ struct anon_vma *folio_anon_vma(const struct folio *folio)
* You can call this for folios which aren't in the swap cache or page
* cache and it will return NULL.
*/
-struct address_space *folio_mapping(struct folio *folio)
+struct address_space *folio_mapping(const struct folio *folio)
{
struct address_space *mapping;
--
2.47.2
