Re: [PATCH 4/4] ext4: reduce unnecessary memory allocation in alloc_flex_gd()

[Jan Kara]

On Wed 18-10-23 19:42:21, Baokun Li wrote:
> When a large flex_bg file system is resized, the number of groups to be
> added may be small, and a large amount of memory that will not be used will
> be allocated. Therefore, resize_bg can be set to the size after the number
> of new_group_data to be used is aligned upwards to the power of 2. This
> does not affect the disk layout after online resize and saves some memory.
> 
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>

Looks good, just one small comment below. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>


> @@ -248,6 +250,14 @@ static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned int flexbg_size)
>  	else
>  		flex_gd->resize_bg = flexbg_size;
>  
> +	/* Avoid allocating new groups that will not be used. */

Perhaps make the comment more understandable like:
	/* Avoid allocating large 'groups' array if not needed */

									Honza
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR