Re: [PATCH 3/4] mm, swap: return early from swap_extend_table_try_free() on first non-zero entry

[Youngjun Park]

On Mon, Jul 20, 2026 at 03:13:41PM +0800, Kemeng Shi wrote:
> Return immediately when the first non-zero swap count is found as
> any non-zero swap count prevents freeing extend_table and further
> iteration is pointless.
> 
> Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
> ---
>  mm/swapfile.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 81c4040912be..3fcbd10c6353 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1530,20 +1530,17 @@ int swap_retry_table_alloc(swp_entry_t entry, gfp_t gfp)
>  static void swap_extend_table_try_free(struct swap_cluster_info *ci)
>  {
>  	unsigned long i;
> -	bool can_free = true;
>  
>  	if (!ci->extend_table)
>  		return;
>  
>  	for (i = 0; i < SWAPFILE_CLUSTER; i++) {
>  		if (ci->extend_table[i])
> -			can_free = false;
> +			return;
>  	}
>  
> -	if (can_free) {
> -		kfree(ci->extend_table);
> -		ci->extend_table = NULL;
> -	}
> +	kfree(ci->extend_table);
> +	ci->extend_table = NULL;
>  }
>  
>  /* Decrease the swap count of one slot, without freeing it */
> -- 
> 2.36.1
> 

LGTM :)
Thanks

Reviewed-by: Youngjun Park <youngjun.park@xxxxxxx>

Youngjun