rmap_t tracks bitwise positions for various page reverse map related flags.
enum could provide more compact representation. This converts these flags
into an enum listing, without any functional change.
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
This applies on v6.5-rc1
include/linux/rmap.h | 26 +++++++-------------------
mm/huge_memory.c | 2 +-
mm/memory.c | 2 +-
mm/migrate.c | 2 +-
mm/rmap.c | 4 ++--
mm/swapfile.c | 2 +-
6 files changed, 13 insertions(+), 25 deletions(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index b87d01660412..aee6ee7ddac6 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -168,30 +168,18 @@ static inline void anon_vma_merge(struct vm_area_struct *vma,
struct anon_vma *folio_get_anon_vma(struct folio *folio);
-/* RMAP flags, currently only relevant for some anon rmap operations. */
-typedef int __bitwise rmap_t;
-
-/*
- * No special request: if the page is a subpage of a compound page, it is
- * mapped via a PTE. The mapped (sub)page is possibly shared between processes.
- */
-#define RMAP_NONE ((__force rmap_t)0)
-
-/* The (sub)page is exclusive to a single process. */
-#define RMAP_EXCLUSIVE ((__force rmap_t)BIT(0))
-
-/*
- * The compound page is not mapped via PTEs, but instead via a single PMD and
- * should be accounted accordingly.
- */
-#define RMAP_COMPOUND ((__force rmap_t)BIT(1))
+enum rmap_flags {
+ RMAP_NONE = 0x0, /* No special request - (sub)page is mapped via a single PTE */
+ RMAP_EXCLUSIVE = 0x1, /* The (sub)page is exclusive to a single process */
+ RMAP_COMPOUND = 0x2, /* The compound page is mapped via a single PMD */
+};
/*
* rmap interfaces called when adding or removing pte of page
*/
void page_move_anon_rmap(struct page *, struct vm_area_struct *);
void page_add_anon_rmap(struct page *, struct vm_area_struct *,
- unsigned long address, rmap_t flags);
+ unsigned long address, enum rmap_flags flags);
void page_add_new_anon_rmap(struct page *, struct vm_area_struct *,
unsigned long address);
void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *,
@@ -202,7 +190,7 @@ void page_remove_rmap(struct page *, struct vm_area_struct *,
bool compound);
void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *,
- unsigned long address, rmap_t flags);
+ unsigned long address, enum rmap_flags flags);
void hugepage_add_new_anon_rmap(struct folio *, struct vm_area_struct *,
unsigned long address);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 965d845d73fc..79a790d1cfa8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3297,7 +3297,7 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new)
pmde = pmd_mkdirty(pmde);
if (PageAnon(new)) {
- rmap_t rmap_flags = RMAP_COMPOUND;
+ enum rmap_flags rmap_flags = RMAP_COMPOUND;
if (!is_readable_migration_entry(entry))
rmap_flags |= RMAP_EXCLUSIVE;
diff --git a/mm/memory.c b/mm/memory.c
index 01f39e8144ef..1710aa6826d4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3717,7 +3717,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
struct folio *swapcache, *folio = NULL;
struct page *page;
struct swap_info_struct *si = NULL;
- rmap_t rmap_flags = RMAP_NONE;
+ enum rmap_flags rmap_flags = RMAP_NONE;
bool exclusive = false;
swp_entry_t entry;
pte_t pte;
diff --git a/mm/migrate.c b/mm/migrate.c
index 24baad2571e3..bdb73b11845a 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -186,7 +186,7 @@ static bool remove_migration_pte(struct folio *folio,
DEFINE_FOLIO_VMA_WALK(pvmw, old, vma, addr, PVMW_SYNC | PVMW_MIGRATION);
while (page_vma_mapped_walk(&pvmw)) {
- rmap_t rmap_flags = RMAP_NONE;
+ enum rmap_flags rmap_flags = RMAP_NONE;
pte_t old_pte;
pte_t pte;
swp_entry_t entry;
diff --git a/mm/rmap.c b/mm/rmap.c
index 0c0d8857dfce..4d4c821d8e56 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1213,7 +1213,7 @@ static void __page_check_anon_rmap(struct page *page,
* (but PageKsm is never downgraded to PageAnon).
*/
void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
- unsigned long address, rmap_t flags)
+ unsigned long address, enum rmap_flags flags)
{
struct folio *folio = page_folio(page);
atomic_t *mapped = &folio->_nr_pages_mapped;
@@ -2539,7 +2539,7 @@ void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc)
* RMAP_COMPOUND is ignored.
*/
void hugepage_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
- unsigned long address, rmap_t flags)
+ unsigned long address, enum rmap_flags flags)
{
struct folio *folio = page_folio(page);
struct anon_vma *anon_vma = vma->anon_vma;
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 8e6dde68b389..3a9b1d8b3151 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1788,7 +1788,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
get_page(page);
if (page == swapcache) {
- rmap_t rmap_flags = RMAP_NONE;
+ enum rmap_flags rmap_flags = RMAP_NONE;
/*
* See do_swap_page(): PageWriteback() would be problematic.
--
2.30.2
