Re: [PATCH -next v3 1/3] block, bfq: record how many queues are busy in bfq_group

["yukuai (C)" <yukuai3@huawei.com>]

在 2022/04/27 20:52, Jan Kara 写道:
> On Wed 27-04-22 20:47:20, Yu Kuai wrote:
>> Prepare to refactor the counting of 'num_groups_with_pending_reqs'.
>>
>> Add a counter 'busy_queues' in bfq_group, and update it in
>> bfq_add/del_bfqq_busy().
>>
>> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> 
> ...
> 
>> diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
>> index f8eb340381cf..53826797430f 100644
>> --- a/block/bfq-wf2q.c
>> +++ b/block/bfq-wf2q.c
>> @@ -218,6 +218,14 @@ static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
>>   	return false;
>>   }
>>   
>> +static void bfq_update_busy_queues(struct bfq_queue *bfqq, bool is_add)
>> +{
>> +	if (is_add)
>> +		bfqq_group(bfqq)->busy_queues++;
>> +	else
>> +		bfqq_group(bfqq)->busy_queues--;
>> +}
>> +
>>   #else /* CONFIG_BFQ_GROUP_IOSCHED */
> 
> I think the bool argument here unnecessarily hurts readability (it's
> difficult to see what the argument means without looking into the
> implementation). I'd rather create two functions bfq_{inc,dec}_busy_queues()
> or if you really insist on a single function, we can have
> bfq_add_busy_queues() and have 'int' argument that will be +1 or -1.

Thanks for the suggestion, I'll create two functions in next iteration.
> 
> 								Honza
>