linux-kernel - Re: [PATCH v2 4/5] mm/memory-failure: move hwpoison

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Date: Sat, 11 May 2024 16:29:03 +0800
From: Miaohe Lin <linmiaohe@...wei.com>
To: Jane Chu <jane.chu@...cle.com>, <nao.horiguchi@...il.com>,
	<akpm@...ux-foundation.org>, <osalvador@...e.de>, <linux-mm@...ck.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 4/5] mm/memory-failure: move hwpoison_filter() higher
 up

On 2024/5/10 14:26, Jane Chu wrote:
> Move hwpoison_filter() higher up as there is no need to spend a lot
> cycles only to find out later that the page is supposed to be skipped
> for hwpoison handling.
> 
> Signed-off-by: Jane Chu <jane.chu@...cle.com>
> ---
>  mm/memory-failure.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 62133c10fb51..2fa884d8b5a3 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2236,6 +2236,13 @@ int memory_failure(unsigned long pfn, int flags)
>  		goto unlock_mutex;
>  	}
>  
> +	if (hwpoison_filter(p)) {
> +		if (flags & MF_COUNT_INCREASED)
> +			put_page(p);
> +		res = -EOPNOTSUPP;
> +		goto unlock_mutex;
> +	}

It might not be a good idea to do hwpoison_filter() here. We don't hold extra page refcnt
yet, so the page state will be really unstable. Or am I miss something?
Thanks.
.