linux-kernel - Re: [PATCH] mm: No need to check pcp page when free it to buddy

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Date:   Wed, 14 Sep 2022 14:19:19 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     "zhaoyang.huang" <zhaoyang.huang@...soc.com>
Cc:     Zhaoyang Huang <huangzhaoyang@...il.com>, <linux-mm@...ck.org>,
        <linux-kernel@...r.kernel.org>, <ke.wang@...soc.com>
Subject: Re: [PATCH] mm: No need to check pcp page when free it to buddy

On Wed, 14 Sep 2022 18:53:40 +0800 "zhaoyang.huang" <zhaoyang.huang@...soc.com> wrote:

> From: Zhaoyang Huang <zhaoyang.huang@...soc.com>
> 
> The pages on pcp list have been checked the validity from each entrance. It is
> no need to check it again when free them back to buddy.
> 

I'm not sure what "from each entrance" means.  Please identify the
codesite where this other check is occurring?

> ---
>  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 e008a3d..131536e 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1445,7 +1445,7 @@ static bool free_pcp_prepare(struct page *page, unsigned int order)
>  
>  static bool bulkfree_pcp_prepare(struct page *page)
>  {
> -	return check_free_page(page);
> +	return false;
>  }
>  #endif /* CONFIG_DEBUG_VM */