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Message-ID: <4b7e4d48-f0f9-c0b0-e8e1-2678d0306252@redhat.com>
Date:   Tue, 23 May 2023 16:00:39 +0200
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Subject: Re: [PATCH v8 1/6] ksm: support unsharing KSM-placed zero pages
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To:     xu xin <xu.xin.sc@gmail.com>
Cc:     akpm@linux-foundation.org, imbrenda@linux.ibm.com,
        jiang.xuexin@zte.com.cn, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, ran.xiaokai@zte.com.cn, xu.xin16@zte.com.cn,
        yang.yang29@zte.com.cn
References: <1925d301-462d-6b33-8867-4e1646b2dbd6@redhat.com>
 <20230523135709.6902-1-xu.xin16@zte.com.cn>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20230523135709.6902-1-xu.xin16@zte.com.cn>
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On 23.05.23 15:57, xu xin wrote:
>>> ---
>>>    include/linux/ksm.h | 6 ++++++
>>>    mm/ksm.c            | 5 +++--
>>>    2 files changed, 9 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/linux/ksm.h b/include/linux/ksm.h
>>> index 899a314bc487..7989200cdbb7 100644
>>> --- a/include/linux/ksm.h
>>> +++ b/include/linux/ksm.h
>>> @@ -26,6 +26,9 @@ int ksm_disable(struct mm_struct *mm);
>>>    
>>>    int __ksm_enter(struct mm_struct *mm);
>>>    void __ksm_exit(struct mm_struct *mm);
>>> +/* use pte_mkdirty to track a KSM-placed zero page */
>>> +#define set_pte_ksm_zero(pte)	pte_mkdirty(pte_mkspecial(pte))
>>
>> If there is only a single user (which I assume), please inline it instead.
> 
> Excuse me, I'm wondering why using inline here instead of macro is better.
> Thanks! :)

Just to clarify: not an inline function but removing the macro 
completely and just place that code directly into the single caller.

Single user, no need to put that into ksm.h -- and I'm not super happy 
about the set_pte_ksm_zero() name ;) because we get the zero-pte already 
passed in from the caller ...

-- 
Thanks,

David / dhildenb