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Message-ID: <f79ad32f-50a3-be1a-0cac-d00f579e7077@linux.alibaba.com>
Date:   Tue, 21 Jun 2022 16:45:39 +0800
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Subject: Re: [PATCH] mm/damon: Use set_huge_pte_at() to make huge pte old
To:     SeongJae Park <sj@kernel.org>
Cc:     akpm@linux-foundation.org, mike.kravetz@oracle.com,
        songmuchun@bytedance.com, damon@lists.linux.dev,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
References: <20220620172742.48766-1-sj@kernel.org>
From:   Baolin Wang <baolin.wang@linux.alibaba.com>
In-Reply-To: <20220620172742.48766-1-sj@kernel.org>
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Hi SeongJae,

On 6/21/2022 1:27 AM, SeongJae Park wrote:
> Hi Baolin,
> 
> On Mon, 20 Jun 2022 10:34:42 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote:
> 
>> The huge_ptep_set_access_flags() can not make the huge pte old according
>> to the discussion [1], that means we will always mornitor the young state
>> of the hugetlb though we stopped accessing the hugetlb, as a result DAMON
>> will get inaccurate accessing statistics.
>>
>> So changing to use set_huge_pte_at() to make the huge pte old to fix this
>> issue.
>>
>> [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/
>>
>> Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages")
> 
> As the commit has merged in from v5.17, I guess it would be better to do below?
> 
> Cc: <stable@vger.kernel.org>

Yes, thanks for reminding. Hope Andrew can help to add the stable tag 
when picking up this patch.

> 
>> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> 
> Other than that,
> 
> Reviewed-by: SeongJae Park <sj@kernel.org>

Thanks.