Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Subject: Re: [PATCH -next v4 1/3] block, bfq: record how many queues are busy
 in bfq_group
To:     Jan Kara <jack@suse.cz>
CC:     <tj@kernel.org>, <axboe@kernel.dk>, <paolo.valente@linaro.org>,
        <cgroups@vger.kernel.org>, <linux-block@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <yi.zhang@huawei.com>
References: <20220428111907.3635820-1-yukuai3@huawei.com>
 <20220428111907.3635820-2-yukuai3@huawei.com>
 <20220428111800.aqfzwwii5dabx3ko@quack3.lan>
From:   "yukuai (C)" <yukuai3@huawei.com>
Message-ID: <00fafd9e-5433-70d8-6493-46a2cc78ec97@huawei.com>
Date:   Thu, 28 Apr 2022 19:27:28 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.8.0
MIME-Version: 1.0
In-Reply-To: <20220428111800.aqfzwwii5dabx3ko@quack3.lan>
Content-Type: text/plain; charset="gbk"; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

?? 2022/04/28 19:18, Jan Kara д??:
> On Thu 28-04-22 19:19:05, 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>
> 
> Just two nits below:
> 
>> --- a/block/bfq-wf2q.c
>> +++ b/block/bfq-wf2q.c
>> @@ -218,6 +218,16 @@ static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
>>   	return false;
>>   }
>>   
>> +static void bfq_add_busy_queues(struct bfq_queue *bfqq)
>> +{
>> +	bfqq_group(bfqq)->busy_queues++;
>> +}
>> +
>> +static void bfq_dec_busy_queues(struct bfq_queue *bfqq)
>> +{
>> +	bfqq_group(bfqq)->busy_queues--;
>> +}
>> +
> 
> An opposite from "decrement" is "increment", not "add". So
> bfq_add_busy_queues() should be bfq_inc_busy_queues().

You are right
> 
>> @@ -230,6 +240,14 @@ static bool bfq_no_longer_next_in_service(struct bfq_entity *entity)
>>   	return true;
>>   }
>>   
>> +static void bfq_add_busy_queues(struct bfq_queue *bfqq)
>> +{
>> +}
>> +
>> +static void bfq_add_busy_queues(struct bfq_queue *bfqq)
>> +{
>> +}
>> +
> 
> You have two times the same function here and you miss the other one...

oops, I forgot to compile without CONFIG_BFQ_GROUP_IOSCHED...

Thanks a lot to spolt this.
Kuai
> 
> 								Honza
>