Re: [PATCH 2/8] io-wq: add helper to merge two wq_lists

[Hao Xu <haoxu@linux.alibaba.com>]

在 2021/9/28 下午7:10, Pavel Begunkov 写道:
> On 9/27/21 7:17 AM, Hao Xu wrote:
>> add a helper to merge two wq_lists, it will be useful in the next
>> patches.
>>
>> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
>> ---
>>   fs/io-wq.h | 20 ++++++++++++++++++++
>>   1 file changed, 20 insertions(+)
>>
>> diff --git a/fs/io-wq.h b/fs/io-wq.h
>> index 8369a51b65c0..7510b05d4a86 100644
>> --- a/fs/io-wq.h
>> +++ b/fs/io-wq.h
>> @@ -39,6 +39,26 @@ static inline void wq_list_add_after(struct io_wq_work_node *node,
>>   		list->last = node;
>>   }
>>   
>> +/**
>> + * wq_list_merge - merge the second list to the first one.
>> + * @list0: the first list
>> + * @list1: the second list
>> + * after merge, list0 contains the merged list.
>> + */
>> +static inline void wq_list_merge(struct io_wq_work_list *list0,
>> +				     struct io_wq_work_list *list1)
>> +{
>> +	if (!list1)
>> +		return;
>> +
>> +	if (!list0) {
>> +		list0 = list1;
> 
> It assigns a local var and returns, the assignment will be compiled
> out, something is wrong
True, I've corrected it in v2.
> 
>> +		return;
>> +	}
>> +	list0->last->next = list1->first;
>> +	list0->last = list1->last;
>> +}
>> +
>>   static inline void wq_list_add_tail(struct io_wq_work_node *node,
>>   				    struct io_wq_work_list *list)
>>   {
>>
>