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Message-ID: <8b358115-67c6-c76a-b0ca-5c44c79218e7@gmail.com>
Date:   Thu, 17 Feb 2022 10:56:11 +0800
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Subject: Re: [RFC V2 5/6] blk-ioprio: make ioprio pluggable and modular
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To:     Bart Van Assche <bvanassche@acm.org>, Jens Axboe <axboe@kernel.dk>
Cc:     hch@infradead.org, Josef Bacik <jbacik@fb.com>,
        Tejun Heo <tj@kernel.org>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220215123705.58968-1-jianchao.wan9@gmail.com>
 <20220215123705.58968-6-jianchao.wan9@gmail.com>
 <cb5677fc-01ac-f97f-ccf8-eb91505ad0e3@acm.org>
 <0608cd82-89c6-8fba-d06b-fdef9c53114f@gmail.com>
 <306b80f7-1185-17b8-fb85-7241823681d0@acm.org>
From:   Wang Jianchao <jianchao.wan9@gmail.com>
In-Reply-To: <306b80f7-1185-17b8-fb85-7241823681d0@acm.org>
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On 2022/2/17 2:01 上午, Bart Van Assche wrote:
> On 2/15/22 18:09, Wang Jianchao wrote:
>> On 2022/2/16 5:26 上午, Bart Van Assche wrote:
>>> On 2/15/22 04:37, Wang Jianchao (Kuaishou) wrote:
>>>> diff --git a/block/Makefile b/block/Makefile
>>>> index f38eaa612929..f6a3995af285 100644
>>>> --- a/block/Makefile
>>>> +++ b/block/Makefile
>>>> @@ -17,7 +17,8 @@ obj-$(CONFIG_BLK_DEV_BSGLIB)    += bsg-lib.o
>>>>    obj-$(CONFIG_BLK_CGROUP)    += blk-cgroup.o
>>>>    obj-$(CONFIG_BLK_CGROUP_RWSTAT)    += blk-cgroup-rwstat.o
>>>>    obj-$(CONFIG_BLK_DEV_THROTTLING)    += blk-throttle.o
>>>> -obj-$(CONFIG_BLK_CGROUP_IOPRIO)    += blk-ioprio.o
>>>> +io-prio-y             := blk-ioprio.o
>>>> +obj-$(CONFIG_BLK_CGROUP_IOPRIO)    += io-prio.o
>>>>    obj-$(CONFIG_BLK_CGROUP_IOLATENCY)    += blk-iolatency.o
>>>>    obj-$(CONFIG_BLK_CGROUP_IOCOST)    += blk-iocost.o
>>>>    obj-$(CONFIG_MQ_IOSCHED_DEADLINE)    += mq-deadline.o
>>>
>>> Is the above change really necessary?
>>
>> Except for making maintaining easier on a running system, removing a
>> rqos policy module with cgroup supporting can release a blk-cgroup
>> policy slots. As BLKCG_MAX_POLS, the max slots number is fixed now.
> 
> It seems like my question was not clear? What I meant is that I think that the above changes are not necessary to build blk-ioprio as a kernel module.
> 
Thanks so much for your kindly remind. I have changed it.

Regards
Jianchao