2020-06-25 23:56:38

by Wei Yang

Subject: [PATCH] mm/page_alloc: fallbacks at most has 3 elements

MIGRAGE_TYPES is used to be the mark of end and there are at most 3
elements for the one dimension array.

Reduce to 3 to save little memory.

Signed-off-by: Wei Yang <[email protected]>
---
mm/page_alloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dabec744ceff..8b0df4aeb8c6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2266,7 +2266,7 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
* This array describes the order lists are fallen back to when
* the free lists for the desirable migrate type are depleted
*/
-static int fallbacks[MIGRATE_TYPES][4] = {
+static int fallbacks[MIGRATE_TYPES][3] = {
[MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
[MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
--
2.20.1 (Apple Git-117)

2020-06-30 13:51:59

by David Hildenbrand

Subject: Re: [PATCH] mm/page_alloc: fallbacks at most has 3 elements

On 26.06.20 01:10, Wei Yang wrote:
> MIGRAGE_TYPES is used to be the mark of end and there are at most 3
> elements for the one dimension array.
>
> Reduce to 3 to save little memory.
>
> Signed-off-by: Wei Yang <[email protected]>
> ---
> mm/page_alloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index dabec744ceff..8b0df4aeb8c6 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2266,7 +2266,7 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
> * This array describes the order lists are fallen back to when
> * the free lists for the desirable migrate type are depleted
> */
> -static int fallbacks[MIGRATE_TYPES][4] = {
> +static int fallbacks[MIGRATE_TYPES][3] = {
> [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
> [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
> [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES },
>

Indeed, looks sane to me.

Reviewed-by: David Hildenbrand <[email protected]>

--
Thanks,

David / dhildenb