Re: [RFC][PATCH 04/10] zsmalloc: cosmetic compaction code adjustments

Minchan Kim
2015-06-04T03:14:27Z

On Sat, May 30, 2015 at 12:05:22AM +0900, Sergey Senozhatsky wrote:
> change zs_object_copy() argument order to be (DST, SRC) rather
> than (SRC, DST). copy/move functions usually have (to, from)
> arguments order.

Yeb,

>
> rename alloc_target_page() to isolate_target_page(). this
> function doesn't allocate anything, it isolates target page,
> pretty much like isolate_source_page().

The reason I named it as alloc_target_page is I had a plan to
alloc new page which might be helpful sometime but I cannot
think of any benefit now so I follow your your patch.

>
> tweak __zs_compact() comment.
>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>

> ---
> mm/zsmalloc.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 9ef6f15..fa72a81 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -1469,7 +1469,7 @@ void zs_free(struct zs_pool *pool, unsigned long handle)
> }
> EXPORT_SYMBOL_GPL(zs_free);
>
> -static void zs_object_copy(unsigned long src, unsigned long dst,
> +static void zs_object_copy(unsigned long dst, unsigned long src,
> struct size_class *class)
> {
> struct page *s_page, *d_page;
> @@ -1610,7 +1610,7 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
>
> used_obj = handle_to_obj(handle);
> free_obj = obj_malloc(d_page, class, handle);
> - zs_object_copy(used_obj, free_obj, class);
> + zs_object_copy(free_obj, used_obj, class);
> index++;
> record_obj(handle, free_obj);
> unpin_tag(handle);
> @@ -1626,7 +1626,7 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class,
> return ret;
> }
>
> -static struct page *alloc_target_page(struct size_class *class)
> +static struct page *isolate_target_page(struct size_class *class)
> {
> int i;
> struct page *page;
> @@ -1714,11 +1714,11 @@ static unsigned long __zs_compact(struct zs_pool *pool,
> cc.index = 0;
> cc.s_page = src_page;
>
> - while ((dst_page = alloc_target_page(class))) {
> + while ((dst_page = isolate_target_page(class))) {
> cc.d_page = dst_page;
> /*
> - * If there is no more space in dst_page, try to
> - * allocate another zspage.
> + * If there is no more space in dst_page, resched
> + * and see if anyone had allocated another zspage.
> */
> if (!migrate_zspage(pool, class, &cc))
> break;
> --
> 2.4.2.337.gfae46aa
>

--
Kind regards,
Minchan Kim