[PATCH v1 0/2] tidy up zsmalloc implementation

[PATCH v1 0/2] tidy up zsmalloc implementation

[Alexey Romanov]

Hello!

This patchset remove some unnecessary checks and adds clarifying 
comment. While analysis zs_object_copy() function code, I spent 
some time to understand what the call kunmap_atomic(d_addr) is for. 
It seems that this point is not trivial and it is worth adding
a comment.

Alexey Romanov (2):
  zsmalloc: zs_object_copy: add clarifying comment
  zsmalloc: remove unnecessary size_class NULL check

 mm/zsmalloc.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

-- 
2.30.1

Re: [PATCH v1 1/2] zsmalloc: zs_object_copy: add clarifying comment

[Sergey Senozhatsky]

On (22/08/11 18:37), Alexey Romanov wrote:
> @@ -1564,6 +1564,12 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
>  		d_off += size;
>  		d_size -= size;
>  
> +		/* Calling kunmap_atomic(d_addr) is necessary. kunmap_atomic() calls
> +		 * must occurs in reverse order of calls to kmap_atomic().
> +		 * So, to call kunmap_atomic(s_addr) we should first call kunmap_atomic(d_addr).
> +		 * For more details see:
> +		 * https://lore.kernel.org/linux-mm/5512421D.4000603@samsung.com/
> +		 */

I'd drop the link part, Emails are not documentation, kmap_atomic
is documented in Documentation/mm/highmem