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Subject: Re: [PATCH] mm/hugetlb: remove a meaningless if statement in gigantic
 page initialization
To:     yanfei.xu@windriver.com, mike.kravetz@oracle.com,
        akpm@linux-foundation.org
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20210202101209.72795-1-yanfei.xu@windriver.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat GmbH
Message-ID: <18d3db7b-da3c-db14-ab99-b2c966c70024@redhat.com>
Date:   Tue, 2 Feb 2021 11:06:09 +0100
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On 02.02.21 11:12, yanfei.xu@windriver.com wrote:
> From: Yanfei Xu <yanfei.xu@windriver.com>
> 
> Gigantic page is a compound page and its order is more than 1.
> Thus it must be available for hpage_pincount. Let's remove this
> meaningless if statement.
> 
> Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
> ---
>   mm/hugetlb.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index a3e4fa2c5e94..73d602f8c7e2 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1501,9 +1501,7 @@ static void prep_compound_gigantic_page(struct page *page, unsigned int order)
>   		set_compound_head(p, page);
>   	}
>   	atomic_set(compound_mapcount_ptr(page), -1);
> -
> -	if (hpage_pincount_available(page))
> -		atomic_set(compound_pincount_ptr(page), 0);
> +	atomic_set(compound_pincount_ptr(page), 0);
>   }
>   
>   /*
> 

I can spot similar handling in destroy_compound_gigantic_page(). If this 
is correct (which I think it is), we should tackle both occurrences at once.

-- 
Thanks,

David / dhildenb