[PATCH 0/2] mm: drop "sub" prefix from various places

[PATCH 0/2] mm: drop "sub" prefix from various places

[Dev Jain]

Patch 1 converts subpage->page : folios have pages, not subpages.

Patch 2 drops "sub" from a function and a variable because the context
is clear enough.

---
These patches were originally in:
https://lore.kernel.org/all/20260526063635.61721-1-dev.jain@arm.com/
as patches 6 and 11. Split out for easing review.

Applies on mm-unstable (81652c5a65d4).

Dev Jain (2):
  mm/swap: rename subpage->page in folio_dup_swap/folio_put_swap
  mm/mprotect: drop 'sub' from batching context

 mm/mprotect.c | 12 ++++++------
 mm/swap.h     |  4 ++--
 mm/swapfile.c | 16 ++++++++--------
 3 files changed, 16 insertions(+), 16 deletions(-)

-- 
2.43.0

[PATCH 1/2] mm/swap: rename subpage->page in folio_dup_swap/folio_put_swap

[Dev Jain]

Folios have pages, not subpages. Rename 'subpage' parameters to 'page'.

Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
 mm/swap.h     |  4 ++--
 mm/swapfile.c | 16 ++++++++--------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/mm/swap.h b/mm/swap.h
index 77d2d14eda421..44ab8e1e595b0 100644
--- a/mm/swap.h
+++ b/mm/swap.h
@@ -230,8 +230,8 @@ extern int swap_retry_table_alloc(swp_entry_t entry, gfp_t gfp);
  * folio_put_swap(): does the opposite thing of folio_dup_swap().
  */
 int folio_alloc_swap(struct folio *folio);
-int folio_dup_swap(struct folio *folio, struct page *subpage);
-void folio_put_swap(struct folio *folio, struct page *subpage);
+int folio_dup_swap(struct folio *folio, struct page *page);
+void folio_put_swap(struct folio *folio, struct page *page);
 
 /* For internal use */
 extern void __swap_cluster_free_entries(struct swap_info_struct *si,
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 78b49b0658add..a602e5820513a 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1781,7 +1781,7 @@ int folio_alloc_swap(struct folio *folio)
 /**
  * folio_dup_swap() - Increase swap count of swap entries of a folio.
  * @folio: folio with swap entries bounded.
- * @subpage: if not NULL, only increase the swap count of this subpage.
+ * @page: if not NULL, only increase the swap count of this page.
  *
  * Typically called when the folio is unmapped and have its swap entry to
  * take its place: Swap entries allocated to a folio has count == 0 and pinned
@@ -1795,7 +1795,7 @@ int folio_alloc_swap(struct folio *folio)
  * swap_put_entries_direct on its swap entry before this helper returns, or
  * the swap count may underflow.
  */
-int folio_dup_swap(struct folio *folio, struct page *subpage)
+int folio_dup_swap(struct folio *folio, struct page *page)
 {
 	swp_entry_t entry = folio->swap;
 	unsigned long nr_pages = folio_nr_pages(folio);
@@ -1803,8 +1803,8 @@ int folio_dup_swap(struct folio *folio, struct page *subpage)
 	VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio);
 	VM_WARN_ON_FOLIO(!folio_test_swapcache(folio), folio);
 
-	if (subpage) {
-		entry.val += folio_page_idx(folio, subpage);
+	if (page) {
+		entry.val += folio_page_idx(folio, page);
 		nr_pages = 1;
 	}
 
@@ -1815,13 +1815,13 @@ int folio_dup_swap(struct folio *folio, struct page *subpage)
 /**
  * folio_put_swap() - Decrease swap count of swap entries of a folio.
  * @folio: folio with swap entries bounded, must be in swap cache and locked.
- * @subpage: if not NULL, only decrease the swap count of this subpage.
+ * @page: if not NULL, only decrease the swap count of this page.
  *
  * This won't free the swap slots even if swap count drops to zero, they are
  * still pinned by the swap cache. User may call folio_free_swap to free them.
  * Context: Caller must ensure the folio is locked and in the swap cache.
  */
-void folio_put_swap(struct folio *folio, struct page *subpage)
+void folio_put_swap(struct folio *folio, struct page *page)
 {
 	swp_entry_t entry = folio->swap;
 	unsigned long nr_pages = folio_nr_pages(folio);
@@ -1830,8 +1830,8 @@ void folio_put_swap(struct folio *folio, struct page *subpage)
 	VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio);
 	VM_WARN_ON_FOLIO(!folio_test_swapcache(folio), folio);
 
-	if (subpage) {
-		entry.val += folio_page_idx(folio, subpage);
+	if (page) {
+		entry.val += folio_page_idx(folio, page);
 		nr_pages = 1;
 	}
 
-- 
2.43.0

[PATCH 2/2] mm/mprotect: drop 'sub' from batching context

[Dev Jain]

Shorten the name of page_anon_exclusive_sub_batch by dropping the
"sub-batch" context - the function itself doesn't need this context.
Similarly, drop "sub" from sub_batch_idx, it is unnecessary and the
usage is clear enough.

Signed-off-by: Dev Jain <dev.jain@arm.com>
---
 mm/mprotect.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 9cbf932b028cf..c0f5ab74bee23 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -143,7 +143,7 @@ static __always_inline void prot_commit_flush_ptes(struct vm_area_struct *vma,
  * !PageAnonExclusive() pages, starting from start_idx. Caller must enforce
  * that the ptes point to consecutive pages of the same anon large folio.
  */
-static __always_inline int page_anon_exclusive_sub_batch(int start_idx, int max_len,
+static __always_inline int page_anon_exclusive_batch(int start_idx, int max_len,
 		struct page *first_page, bool expected_anon_exclusive)
 {
 	int idx;
@@ -174,16 +174,16 @@ static __always_inline void commit_anon_folio_batch(struct vm_area_struct *vma,
 		pte_t oldpte, pte_t ptent, int nr_ptes, struct mmu_gather *tlb)
 {
 	bool expected_anon_exclusive;
-	int sub_batch_idx = 0;
+	int batch_idx = 0;
 	int len;
 
 	while (nr_ptes) {
-		expected_anon_exclusive = PageAnonExclusive(first_page + sub_batch_idx);
-		len = page_anon_exclusive_sub_batch(sub_batch_idx, nr_ptes,
+		expected_anon_exclusive = PageAnonExclusive(first_page + batch_idx);
+		len = page_anon_exclusive_batch(batch_idx, nr_ptes,
 					first_page, expected_anon_exclusive);
 		prot_commit_flush_ptes(vma, addr, ptep, oldpte, ptent, len,
-				       sub_batch_idx, expected_anon_exclusive, tlb);
-		sub_batch_idx += len;
+				       batch_idx, expected_anon_exclusive, tlb);
+		batch_idx += len;
 		nr_ptes -= len;
 	}
 }
-- 
2.43.0

Re: [PATCH 1/2] mm/swap: rename subpage->page in folio_dup_swap/folio_put_swap

[Lance Yang]

On Tue, Jun 23, 2026 at 12:57:21PM +0000, Dev Jain wrote:
>Folios have pages, not subpages. Rename 'subpage' parameters to 'page'.
>
>Acked-by: David Hildenbrand (Arm) <david@kernel.org>
>Signed-off-by: Dev Jain <dev.jain@arm.com>
>---

Just rename cleanup. Didn't see anything off, feel free to add:
Reviewed-by: Lance Yang <lance.yang@linux.dev>

Re: [PATCH 2/2] mm/mprotect: drop 'sub' from batching context

[Lance Yang]

On Tue, Jun 23, 2026 at 12:57:22PM +0000, Dev Jain wrote:
>Shorten the name of page_anon_exclusive_sub_batch by dropping the
>"sub-batch" context - the function itself doesn't need this context.
>Similarly, drop "sub" from sub_batch_idx, it is unnecessary and the
>usage is clear enough.
>
>Signed-off-by: Dev Jain <dev.jain@arm.com>
>---

Rename-only cleanup. Nothing jumped out, feel free to add:

Reviewed-by: Lance Yang <lance.yang@linux.dev>

Re: [PATCH 2/2] mm/mprotect: drop 'sub' from batching context

[Pedro Falcato]

On Tue, Jun 23, 2026 at 12:57:22PM +0000, Dev Jain wrote:
> Shorten the name of page_anon_exclusive_sub_batch by dropping the
> "sub-batch" context - the function itself doesn't need this context.
> Similarly, drop "sub" from sub_batch_idx, it is unnecessary and the
> usage is clear enough.
> 
> Signed-off-by: Dev Jain <dev.jain@arm.com>

Reviewed-by: Pedro Falcato <pfalcato@suse.de>

This is less confusing, thanks!

-- 
Pedro

Re: [PATCH 1/2] mm/swap: rename subpage->page in folio_dup_swap/folio_put_swap

[Pedro Falcato]

On Tue, Jun 23, 2026 at 12:57:21PM +0000, Dev Jain wrote:
> Folios have pages, not subpages. Rename 'subpage' parameters to 'page'.
> 
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> Signed-off-by: Dev Jain <dev.jain@arm.com>

Acked-by: Pedro Falcato <pfalcato@suse.de>

-- 
Pedro

Re: [PATCH 1/2] mm/swap: rename subpage->page in folio_dup_swap/folio_put_swap

[Lorenzo Stoakes]

On Tue, Jun 23, 2026 at 12:57:21PM +0000, Dev Jain wrote:
> Folios have pages, not subpages. Rename 'subpage' parameters to 'page'.
>
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> Signed-off-by: Dev Jain <dev.jain@arm.com>

This subpatch of your series LGTM! ;) so:

Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>

Thanks, Lorenzo

> ---
>  mm/swap.h     |  4 ++--
>  mm/swapfile.c | 16 ++++++++--------
>  2 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/mm/swap.h b/mm/swap.h
> index 77d2d14eda421..44ab8e1e595b0 100644
> --- a/mm/swap.h
> +++ b/mm/swap.h
> @@ -230,8 +230,8 @@ extern int swap_retry_table_alloc(swp_entry_t entry, gfp_t gfp);
>   * folio_put_swap(): does the opposite thing of folio_dup_swap().
>   */
>  int folio_alloc_swap(struct folio *folio);
> -int folio_dup_swap(struct folio *folio, struct page *subpage);
> -void folio_put_swap(struct folio *folio, struct page *subpage);
> +int folio_dup_swap(struct folio *folio, struct page *page);
> +void folio_put_swap(struct folio *folio, struct page *page);
>
>  /* For internal use */
>  extern void __swap_cluster_free_entries(struct swap_info_struct *si,
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 78b49b0658add..a602e5820513a 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1781,7 +1781,7 @@ int folio_alloc_swap(struct folio *folio)
>  /**
>   * folio_dup_swap() - Increase swap count of swap entries of a folio.
>   * @folio: folio with swap entries bounded.
> - * @subpage: if not NULL, only increase the swap count of this subpage.
> + * @page: if not NULL, only increase the swap count of this page.
>   *
>   * Typically called when the folio is unmapped and have its swap entry to
>   * take its place: Swap entries allocated to a folio has count == 0 and pinned
> @@ -1795,7 +1795,7 @@ int folio_alloc_swap(struct folio *folio)
>   * swap_put_entries_direct on its swap entry before this helper returns, or
>   * the swap count may underflow.
>   */
> -int folio_dup_swap(struct folio *folio, struct page *subpage)
> +int folio_dup_swap(struct folio *folio, struct page *page)
>  {
>  	swp_entry_t entry = folio->swap;
>  	unsigned long nr_pages = folio_nr_pages(folio);
> @@ -1803,8 +1803,8 @@ int folio_dup_swap(struct folio *folio, struct page *subpage)
>  	VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio);
>  	VM_WARN_ON_FOLIO(!folio_test_swapcache(folio), folio);
>
> -	if (subpage) {
> -		entry.val += folio_page_idx(folio, subpage);
> +	if (page) {
> +		entry.val += folio_page_idx(folio, page);
>  		nr_pages = 1;
>  	}
>
> @@ -1815,13 +1815,13 @@ int folio_dup_swap(struct folio *folio, struct page *subpage)
>  /**
>   * folio_put_swap() - Decrease swap count of swap entries of a folio.
>   * @folio: folio with swap entries bounded, must be in swap cache and locked.
> - * @subpage: if not NULL, only decrease the swap count of this subpage.
> + * @page: if not NULL, only decrease the swap count of this page.
>   *
>   * This won't free the swap slots even if swap count drops to zero, they are
>   * still pinned by the swap cache. User may call folio_free_swap to free them.
>   * Context: Caller must ensure the folio is locked and in the swap cache.
>   */
> -void folio_put_swap(struct folio *folio, struct page *subpage)
> +void folio_put_swap(struct folio *folio, struct page *page)
>  {
>  	swp_entry_t entry = folio->swap;
>  	unsigned long nr_pages = folio_nr_pages(folio);
> @@ -1830,8 +1830,8 @@ void folio_put_swap(struct folio *folio, struct page *subpage)
>  	VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio);
>  	VM_WARN_ON_FOLIO(!folio_test_swapcache(folio), folio);
>
> -	if (subpage) {
> -		entry.val += folio_page_idx(folio, subpage);
> +	if (page) {
> +		entry.val += folio_page_idx(folio, page);
>  		nr_pages = 1;
>  	}
>
> --
> 2.43.0
>

Re: [PATCH 2/2] mm/mprotect: drop 'sub' from batching context

[Lorenzo Stoakes]

On Tue, Jun 23, 2026 at 12:57:22PM +0000, Dev Jain wrote:
> Shorten the name of page_anon_exclusive_sub_batch by dropping the
> "sub-batch" context - the function itself doesn't need this context.
> Similarly, drop "sub" from sub_batch_idx, it is unnecessary and the
> usage is clear enough.
>
> Signed-off-by: Dev Jain <dev.jain@arm.com>

LGTM, so:

Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>

> ---
>  mm/mprotect.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 9cbf932b028cf..c0f5ab74bee23 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -143,7 +143,7 @@ static __always_inline void prot_commit_flush_ptes(struct vm_area_struct *vma,
>   * !PageAnonExclusive() pages, starting from start_idx. Caller must enforce
>   * that the ptes point to consecutive pages of the same anon large folio.
>   */
> -static __always_inline int page_anon_exclusive_sub_batch(int start_idx, int max_len,
> +static __always_inline int page_anon_exclusive_batch(int start_idx, int max_len,
>  		struct page *first_page, bool expected_anon_exclusive)
>  {
>  	int idx;
> @@ -174,16 +174,16 @@ static __always_inline void commit_anon_folio_batch(struct vm_area_struct *vma,
>  		pte_t oldpte, pte_t ptent, int nr_ptes, struct mmu_gather *tlb)
>  {
>  	bool expected_anon_exclusive;
> -	int sub_batch_idx = 0;
> +	int batch_idx = 0;
>  	int len;
>
>  	while (nr_ptes) {
> -		expected_anon_exclusive = PageAnonExclusive(first_page + sub_batch_idx);
> -		len = page_anon_exclusive_sub_batch(sub_batch_idx, nr_ptes,
> +		expected_anon_exclusive = PageAnonExclusive(first_page + batch_idx);
> +		len = page_anon_exclusive_batch(batch_idx, nr_ptes,
>  					first_page, expected_anon_exclusive);
>  		prot_commit_flush_ptes(vma, addr, ptep, oldpte, ptent, len,
> -				       sub_batch_idx, expected_anon_exclusive, tlb);
> -		sub_batch_idx += len;
> +				       batch_idx, expected_anon_exclusive, tlb);
> +		batch_idx += len;
>  		nr_ptes -= len;
>  	}
>  }
> --
> 2.43.0
>

Re: [PATCH 1/2] mm/swap: rename subpage->page in folio_dup_swap/folio_put_swap

[Nhat Pham]

On Tue, Jun 23, 2026 at 5:57 AM Dev Jain <dev.jain@arm.com> wrote:
>
> Folios have pages, not subpages. Rename 'subpage' parameters to 'page'.
>
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> Signed-off-by: Dev Jain <dev.jain@arm.com>

Reviewed-by: Nhat Pham <nphamcs@gmail.com>

Re: [PATCH 2/2] mm/mprotect: drop 'sub' from batching context

[David Hildenbrand (Arm)]

On 6/23/26 14:57, Dev Jain wrote:
> Shorten the name of page_anon_exclusive_sub_batch by dropping the
> "sub-batch" context - the function itself doesn't need this context.
> Similarly, drop "sub" from sub_batch_idx, it is unnecessary and the
> usage is clear enough.
> 
> Signed-off-by: Dev Jain <dev.jain@arm.com>
> ---

Acked-by: David Hildenbrand (Arm) <david@kernel.org>

-- 
Cheers,

David