Message-ID: <b3eff456-4c3d-3908-178f-4d9d6d4b23c7@huawei.com>
Date:   Mon, 6 Mar 2023 09:12:38 +0800
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Subject: Re: [PATCH v2 3/3] mm/damon/paddr: minor refactor of
 damon_pa_mark_accessed_or_deactivate()
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To:     SeongJae Park <sj@kernel.org>
CC:     Andrew Morton <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, <damon@lists.linux.dev>
References: <20230303183722.113464-1-sj@kernel.org>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
In-Reply-To: <20230303183722.113464-1-sj@kernel.org>
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On 2023/3/4 2:37, SeongJae Park wrote:
> On Fri, 3 Mar 2023 18:26:33 +0000 SeongJae Park <sj@kernel.org> wrote:
> 
>> On Fri, 3 Mar 2023 16:43:43 +0800 Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>>
>>> Omit one line by unified folio_put(), and make code more clear.
>>>
>>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>>> ---
>>>   mm/damon/paddr.c | 9 ++++-----
>>>   1 file changed, 4 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
>>> index 2ef9db0189ca..6930ebf3667c 100644
>>> --- a/mm/damon/paddr.c
>>> +++ b/mm/damon/paddr.c
>>> @@ -266,17 +266,16 @@ static inline unsigned long damon_pa_mark_accessed_or_deactivate(
>>>   		if (!folio)
>>>   			continue;
>>>   
>>> -		if (damos_pa_filter_out(s, folio)) {
>>> -			folio_put(folio);
>>> -			continue;
>>> -		}
>>> +		if (damos_pa_filter_out(s, folio))
>>> +			goto put_folio;
>>>   
>>>   		if (mark_accessed)
>>>   			folio_mark_accessed(folio);
>>>   		else
>>>   			folio_deactivate(folio);
>>> -		folio_put(folio);
>>>   		applied += folio_nr_pages(folio);
>>> +put_folio:
>>> +		folio_put(folio);
>>
>> I think this change is ok, but shouldn't the 'folio_put()' have called before
> 
> s/before/after/
> 
>> 'folio_nr_pages()' anyway?  If so, could we make the change as a separate fix
>> first, and then make this change, so that it can be easily applied to relevant
>> stable kernels?

Yes, seem to previous one.
>>
>>
>> Thanks,
>> SJ
>>
>>>   	}
>>>   	return applied * PAGE_SIZE;
>>>   }
>>> -- 
>>> 2.35.3
>>>
>>>