[PATCH 0/4] mm/zswap: misc cleanup of code and documentations

[PATCH 0/4] mm/zswap: misc cleanup of code and documentations

[SeongJae Park]

Cleanup an unnecessary local variable write in incompressible pages
handling, typos (s/zwap/zswap/) and outdated comments/documentations
about the zswap's red-black tree, which is replaced by xarray.

SeongJae Park (4):
  mm/zswap: remove unnecessary dlen writes for incompressible pages
  mm/zswap: fix typos: s/zwap/zswap/
  mm/zswap: s/red-black tree/xarray/
  Docs/admin-guide/mm/zswap: s/red-black tree/xarray/

 Documentation/admin-guide/mm/zswap.rst | 10 +++++-----
 mm/memcontrol.c                        |  2 +-
 mm/zswap.c                             |  7 +++----
 3 files changed, 9 insertions(+), 10 deletions(-)


base-commit: 2e943d9cc1fdd399a2f95d1c1d6b865d04bfa239
-- 
2.39.5

[PATCH 2/4] mm/zswap: fix typos: s/zwap/zswap/

[SeongJae Park]

As the subject says.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/memcontrol.c | 2 +-
 mm/zswap.c      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 69c970554e85..74b1bc2252b6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5421,7 +5421,7 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg)
  * @size: size of compressed object
  *
  * This forces the charge after obj_cgroup_may_zswap() allowed
- * compression and storage in zwap for this cgroup to go ahead.
+ * compression and storage in zswap for this cgroup to go ahead.
  */
 void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size)
 {
diff --git a/mm/zswap.c b/mm/zswap.c
index 80619c8589a7..f6b1c8832a4f 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -879,7 +879,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
 	 * acomp instance, then get those requests done simultaneously. but in this
 	 * case, zswap actually does store and load page by page, there is no
 	 * existing method to send the second page before the first page is done
-	 * in one thread doing zwap.
+	 * in one thread doing zswap.
 	 * but in different threads running on different cpu, we have different
 	 * acomp instance, so multiple threads can do (de)compression in parallel.
 	 */
@@ -1128,7 +1128,7 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
 	 *
 	 * 1. We extract the swp_entry_t to the stack, allowing
 	 *    zswap_writeback_entry() to pin the swap entry and
-	 *    then validate the zwap entry against that swap entry's
+	 *    then validate the zswap entry against that swap entry's
 	 *    tree using pointer value comparison. Only when that
 	 *    is successful can the entry be dereferenced.
 	 *
-- 
2.39.5

Re: [PATCH 2/4] mm/zswap: fix typos: s/zwap/zswap/

[Yosry Ahmed]

On Fri, Oct 03, 2025 at 01:38:49PM -0700, SeongJae Park wrote:
> As the subject says.
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>

Acked-by: Yosry Ahmed <yosry.ahmed@linux.dev>

> ---
>  mm/memcontrol.c | 2 +-
>  mm/zswap.c      | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 69c970554e85..74b1bc2252b6 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -5421,7 +5421,7 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg)
>   * @size: size of compressed object
>   *
>   * This forces the charge after obj_cgroup_may_zswap() allowed
> - * compression and storage in zwap for this cgroup to go ahead.
> + * compression and storage in zswap for this cgroup to go ahead.
>   */
>  void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size)
>  {
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 80619c8589a7..f6b1c8832a4f 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -879,7 +879,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
>  	 * acomp instance, then get those requests done simultaneously. but in this
>  	 * case, zswap actually does store and load page by page, there is no
>  	 * existing method to send the second page before the first page is done
> -	 * in one thread doing zwap.
> +	 * in one thread doing zswap.
>  	 * but in different threads running on different cpu, we have different
>  	 * acomp instance, so multiple threads can do (de)compression in parallel.
>  	 */
> @@ -1128,7 +1128,7 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
>  	 *
>  	 * 1. We extract the swp_entry_t to the stack, allowing
>  	 *    zswap_writeback_entry() to pin the swap entry and
> -	 *    then validate the zwap entry against that swap entry's
> +	 *    then validate the zswap entry against that swap entry's
>  	 *    tree using pointer value comparison. Only when that
>  	 *    is successful can the entry be dereferenced.
>  	 *
> -- 
> 2.39.5

Re: [PATCH 2/4] mm/zswap: fix typos: s/zwap/zswap/

[Nhat Pham]

On Fri, Oct 3, 2025 at 1:38 PM SeongJae Park <sj@kernel.org> wrote:
>
> As the subject says.
>
> Signed-off-by: SeongJae Park <sj@kernel.org>

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

Re: [PATCH 2/4] mm/zswap: fix typos: s/zwap/zswap/

[Chengming Zhou]

On 2025/10/4 04:38, SeongJae Park wrote:
> As the subject says.
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>

Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>

> ---
>   mm/memcontrol.c | 2 +-
>   mm/zswap.c      | 4 ++--
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 69c970554e85..74b1bc2252b6 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -5421,7 +5421,7 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg)
>    * @size: size of compressed object
>    *
>    * This forces the charge after obj_cgroup_may_zswap() allowed
> - * compression and storage in zwap for this cgroup to go ahead.
> + * compression and storage in zswap for this cgroup to go ahead.
>    */
>   void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size)
>   {
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 80619c8589a7..f6b1c8832a4f 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -879,7 +879,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
>   	 * acomp instance, then get those requests done simultaneously. but in this
>   	 * case, zswap actually does store and load page by page, there is no
>   	 * existing method to send the second page before the first page is done
> -	 * in one thread doing zwap.
> +	 * in one thread doing zswap.
>   	 * but in different threads running on different cpu, we have different
>   	 * acomp instance, so multiple threads can do (de)compression in parallel.
>   	 */
> @@ -1128,7 +1128,7 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
>   	 *
>   	 * 1. We extract the swp_entry_t to the stack, allowing
>   	 *    zswap_writeback_entry() to pin the swap entry and
> -	 *    then validate the zwap entry against that swap entry's
> +	 *    then validate the zswap entry against that swap entry's
>   	 *    tree using pointer value comparison. Only when that
>   	 *    is successful can the entry be dereferenced.
>   	 *