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Subject: Re: [PATCH] mm/page_alloc: fallbacks at most has 3 elements
To:     Wei Yang <richard.weiyang@linux.alibaba.com>,
        akpm@linux-foundation.org
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20200625231022.18784-1-richard.weiyang@linux.alibaba.com>
From:   David Hildenbrand <david@redhat.com>
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Organization: Red Hat GmbH
Message-ID: <cfe90358-94df-9cb6-5d4e-18a67aa47e49@redhat.com>
Date:   Tue, 30 Jun 2020 15:31:20 +0200
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Sender: linux-kernel-owner@vger.kernel.org
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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 <richard.weiyang@linux.alibaba.com>
> ---
>  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 <david@redhat.com>

-- 
Thanks,

David / dhildenb