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Message-ID: <830328dd-ddb6-bdc5-2d74-35b5212cc569@bytedance.com>
Date:   Tue, 16 May 2023 08:46:24 +0800
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Subject: Re: [PATCH 06/10] maple_tree: Wrap the replace operation with an
 inline function.
To:     "Liam R. Howlett" <Liam.Howlett@Oracle.com>
References: <20230515131757.60035-1-zhangpeng.00@bytedance.com>
 <20230515131757.60035-7-zhangpeng.00@bytedance.com>
 <20230515170722.6eqyckjaggw5wijq@revolver>
Cc:     Peng Zhang <zhangpeng.00@bytedance.com>, akpm@linux-foundation.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        maple-tree@lists.infradead.org
From:   Peng Zhang <zhangpeng.00@bytedance.com>
In-Reply-To: <20230515170722.6eqyckjaggw5wijq@revolver>
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在 2023/5/16 01:07, Liam R. Howlett 写道:
> * Peng Zhang <zhangpeng.00@bytedance.com> [230515 09:18]:
>> To make mas_wr_modify() cleaner, wrap the replace operation with an
>> inline function.
> 
> mas_wr_modify() is already pretty small.  Is there any reason you want
> this in its own function besides it looking cleaner?
I just want to make the four fast paths in mas_wr_modify()
look uniform without any functional effect.
> 
>>
>> Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
>> ---
>>   lib/maple_tree.c | 21 +++++++++++++++------
>>   1 file changed, 15 insertions(+), 6 deletions(-)
>>
>> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
>> index 4c649d75a4923..ce695adc670ec 100644
>> --- a/lib/maple_tree.c
>> +++ b/lib/maple_tree.c
>> @@ -4288,6 +4288,19 @@ static inline void mas_wr_extend_null(struct ma_wr_state *wr_mas)
>>   	}
>>   }
>>   
>> +static inline bool mas_wr_replace(struct ma_wr_state *wr_mas)
>> +{
>> +	struct ma_state *mas = wr_mas->mas;
>> +
>> +	if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
>> +		rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
>> +		if (!!wr_mas->entry ^ !!wr_mas->content)
>> +			mas_update_gap(mas);
>> +		return true;
>> +	}
>> +	return false;
>> +}
>> +
>>   static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
>>   {
>>   	unsigned char end = wr_mas->node_end;
>> @@ -4347,13 +4360,9 @@ static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
>>   	unsigned char node_size;
>>   	struct ma_state *mas = wr_mas->mas;
>>   
>> -	/* Direct replacement */
>> -	if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
>> -		rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
>> -		if (!!wr_mas->entry ^ !!wr_mas->content)
>> -			mas_update_gap(mas);
>> +	/* Attempt to direct replace */
>> +	if (mas_wr_replace(wr_mas))
>>   		return;
>> -	}
>>   
>>   	/* Attempt to append */
>>   	node_slots = mt_slots[wr_mas->type];
>> -- 
>> 2.20.1
>>