From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yufen Yu Subject: Re: [PATCH v3 00/11] md/raid5: set STRIPE_SIZE as a configurable value Date: Thu, 4 Jun 2020 21:17:21 +0800 Message-ID: <72b83f59-db43-6809-d975-4ec3c2c83cd4@huawei.com> References: <20200527131933.34400-1-yuyufen@huawei.com> <71f662d7-9aee-a130-c41d-67a691514ef6@cloud.ionos.com> <555121b6-fe76-4827-7b8f-7a22ba04ed82@huawei.com> <9acfb512-88ee-b4b0-88d4-94841e72d31a@cloud.ionos.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-raid-owner@vger.kernel.org To: Song Liu , Guoqing Jiang Cc: linux-raid , NeilBrown , Coly Li , Xiao Ni , Hou Tao List-Id: linux-raid.ids On 2020/6/2 14:59, Song Liu wrote: >> I do think the flexibility is not enough, if someone set stripe size to >> 64KB by any chance, >> people could complain the performance of raid5 really sucks if the io is >> not big. And it is >> not realistic to let people rebuild the module in case the io size is >> changed, so it would be >> more helpful if the stripe size can be changed dynamically without >> recompile code. > > Agreed that it is not ideal to recompile the kernel/module to change stripe > size. It is also possible that multiple arrays in one system have different > optimal stripe sizes. I guess it shouldn't be too complicated to make this > configurable per array? > Yeah. Thanks a lot for suggestion. I admit that the current implementation is really not good. To make it more flexible and provide each stripe_size for raid arrays, I plan to move stripe_size into r5conf and make it dynamically changeable by sysfs interface. Thanks, Yufen