On Fri, 3 Feb 2023 18:01:32 +0800 Yajun Deng <yajun.deng@xxxxxxxxx> wrote:
> The commit 1dd214b8f21c ("mm: page_alloc: avoid merging non-fallbackable
> pageblocks with others") has removed MIGRATE_CMA and MIGRATE_ISOLATE from
> fallbacks list. so there is no need to add an element at the end of every
> type.
>
> Reduce fallbacks to (MIGRATE_PCPTYPES - 1).
Thanks. `git log' suggests who should be cc'ed when fixing things...
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2603,10 +2603,10 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
> *
> * The other migratetypes do not have fallbacks.
> */
> -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 },
> +static int fallbacks[MIGRATE_TYPES][MIGRATE_PCPTYPES - 1] = {
> + [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE },
> + [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE },
> + [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE },
> };
>
> #ifdef CONFIG_CMA
> @@ -2865,11 +2865,8 @@ int find_suitable_fallback(struct free_area *area, unsigned int order,
> return -1;
>
> *can_steal = false;
> - for (i = 0;; i++) {
> + for (i = 0; i < MIGRATE_PCPTYPES - 1 ; i++) {
> fallback_mt = fallbacks[migratetype][i];
> - if (fallback_mt == MIGRATE_TYPES)
> - break;
> -
> if (free_area_empty(area, fallback_mt))
> continue;
>
> --
> 2.25.1
