zspage migration can terminate as soon as it moves the last
allocated object from the source zspage.  Add a simple helper
zspage_empty() that tests zspage ->inuse on each migration
iteration.

Suggested-by: Alexey Romanov <AVRomanov@sberdevices.ru>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 mm/zsmalloc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 3f057970504e..5d60eaedc3b7 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1147,6 +1147,11 @@ static bool zspage_full(struct size_class *class, struct zspage *zspage)
 	return get_zspage_inuse(zspage) == class->objs_per_zspage;
 }
 
+static bool zspage_empty(struct zspage *zspage)
+{
+	return get_zspage_inuse(zspage) == 0;
+}
+
 /**
  * zs_lookup_class_index() - Returns index of the zsmalloc &size_class
  * that hold objects of the provided size.
@@ -1625,6 +1630,10 @@ static void migrate_zspage(struct zs_pool *pool, struct size_class *class,
 		obj_idx++;
 		record_obj(handle, free_obj);
 		obj_free(class->size, used_obj);
+
+		/* Stop if there are no more objects to migrate */
+		if (zspage_empty(get_zspage(s_page)))
+			break;
 	}
 
 	/* Remember last position in this iteration */
-- 
2.41.0.162.gfafddb0af9-goog

On Sat, Jun 24, 2023 at 02:12:14PM +0900, Sergey Senozhatsky wrote:
> zspage migration can terminate as soon as it moves the last
> allocated object from the source zspage.  Add a simple helper
> zspage_empty() that tests zspage ->inuse on each migration
> iteration.
> 
> Suggested-by: Alexey Romanov <AVRomanov@sberdevices.ru>
> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>

Hi,

On Sat, Jun 24, 2023 at 02:12:14PM +0900, Sergey Senozhatsky wrote:
> zspage migration can terminate as soon as it moves the last
> allocated object from the source zspage.  Add a simple helper
> zspage_empty() that tests zspage ->inuse on each migration
> iteration.
> 
> Suggested-by: Alexey Romanov <AVRomanov@sberdevices.ru>
> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> ---
>  mm/zsmalloc.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 3f057970504e..5d60eaedc3b7 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -1147,6 +1147,11 @@ static bool zspage_full(struct size_class *class, struct zspage *zspage)
>  	return get_zspage_inuse(zspage) == class->objs_per_zspage;
>  }
>  
> +static bool zspage_empty(struct zspage *zspage)
> +{
> +	return get_zspage_inuse(zspage) == 0;
> +}
> +
>  /**
>   * zs_lookup_class_index() - Returns index of the zsmalloc &size_class
>   * that hold objects of the provided size.
> @@ -1625,6 +1630,10 @@ static void migrate_zspage(struct zs_pool *pool, struct size_class *class,
>  		obj_idx++;
>  		record_obj(handle, free_obj);
>  		obj_free(class->size, used_obj);
> +
> +		/* Stop if there are no more objects to migrate */
> +		if (zspage_empty(get_zspage(s_page)))
> +			break;
>  	}
>  
>  	/* Remember last position in this iteration */
> -- 
> 2.41.0.162.gfafddb0af9-goog
> 

not sure if I can keep this tag but,

Reviewed-by: Alexey Romanov <avromanov@sberdevices.ru>

-- 
Thank you,
Alexey

On (23/06/26 10:57), Alexey Romanov wrote:
> not sure if I can keep this tag but,

Sure, why not

> 
> Reviewed-by: Alexey Romanov <avromanov@sberdevices.ru>