From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 057A6C433EF for ; Fri, 8 Apr 2022 06:52:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229446AbiDHGx7 (ORCPT ); Fri, 8 Apr 2022 02:53:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiDHGxu (ORCPT ); Fri, 8 Apr 2022 02:53:50 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6F4676E34; Thu, 7 Apr 2022 23:50:51 -0700 (PDT) Received: from kwepemi500001.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KZTLN5NYTzBrWj; Fri, 8 Apr 2022 14:46:36 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi500001.china.huawei.com (7.221.188.114) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 8 Apr 2022 14:50:49 +0800 Received: from [10.174.176.73] (10.174.176.73) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 8 Apr 2022 14:50:48 +0800 Subject: Re: [PATCH -next 00/11] support concurrent sync io for bfq on a specail occasion From: "yukuai (C)" To: , , , CC: , , , References: <20220305091205.4188398-1-yukuai3@huawei.com> <11fda851-a552-97ea-d083-d0288c17ba53@huawei.com> <81cfac80-83f6-7381-d4ad-560dfcdd9a9d@huawei.com> Message-ID: Date: Fri, 8 Apr 2022 14:50:47 +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: <81cfac80-83f6-7381-d4ad-560dfcdd9a9d@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.73] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org friendly ping ... 在 2022/04/01 11:43, yukuai (C) 写道: > friendly ping ... > > 在 2022/03/25 15:30, yukuai (C) 写道: >> friendly ping ... >> >> 在 2022/03/17 9:49, yukuai (C) 写道: >>> friendly ping ... >>> >>> 在 2022/03/11 14:31, yukuai (C) 写道: >>>> friendly ping ... >>>> >>>> 在 2022/03/05 17:11, Yu Kuai 写道: >>>>> Currently, bfq can't handle sync io concurrently as long as they >>>>> are not issued from root group. This is because >>>>> 'bfqd->num_groups_with_pending_reqs > 0' is always true in >>>>> bfq_asymmetric_scenario(). >>>>> >>>>> This patchset tries to support concurrent sync io if all the sync ios >>>>> are issued from the same cgroup: >>>>> >>>>> 1) Count root_group into 'num_groups_with_pending_reqs', patch 1-5; >>>>> >>>>> 2) Don't idle if 'num_groups_with_pending_reqs' is 1, patch 6; >>>>> >>>>> 3) Don't count the group if the group doesn't have pending requests, >>>>> while it's child groups may have pending requests, patch 7; >>>>> >>>>> This is because, for example: >>>>> if sync ios are issued from cgroup /root/c1/c2, root, c1 and c2 >>>>> will all be counted into 'num_groups_with_pending_reqs', >>>>> which makes it impossible to handle sync ios concurrently. >>>>> >>>>> 4) Decrease 'num_groups_with_pending_reqs' when the last queue >>>>> completes >>>>> all the requests, while child groups may still have pending >>>>> requests, patch 8-10; >>>>> >>>>> This is because, for example: >>>>> t1 issue sync io on root group, t2 and t3 issue sync io on the same >>>>> child group. num_groups_with_pending_reqs is 2 now. >>>>> After t1 stopped, num_groups_with_pending_reqs is still 2. sync io >>>>> from >>>>> t2 and t3 still can't be handled concurrently. >>>>> >>>>> fio test script: startdelay is used to avoid queue merging >>>>> [global] >>>>> filename=/dev/nvme0n1 >>>>> allow_mounted_write=0 >>>>> ioengine=psync >>>>> direct=1 >>>>> ioscheduler=bfq >>>>> offset_increment=10g >>>>> group_reporting >>>>> rw=randwrite >>>>> bs=4k >>>>> >>>>> [test1] >>>>> numjobs=1 >>>>> >>>>> [test2] >>>>> startdelay=1 >>>>> numjobs=1 >>>>> >>>>> [test3] >>>>> startdelay=2 >>>>> numjobs=1 >>>>> >>>>> [test4] >>>>> startdelay=3 >>>>> numjobs=1 >>>>> >>>>> [test5] >>>>> startdelay=4 >>>>> numjobs=1 >>>>> >>>>> [test6] >>>>> startdelay=5 >>>>> numjobs=1 >>>>> >>>>> [test7] >>>>> startdelay=6 >>>>> numjobs=1 >>>>> >>>>> [test8] >>>>> startdelay=7 >>>>> numjobs=1 >>>>> >>>>> test result: >>>>> running fio on root cgroup >>>>> v5.17-rc6:       550 Mib/s >>>>> v5.17-rc6-patched: 550 Mib/s >>>>> >>>>> running fio on non-root cgroup >>>>> v5.17-rc6:       349 Mib/s >>>>> v5.17-rc6-patched: 550 Mib/s >>>>> >>>>> Yu Kuai (11): >>>>>    block, bfq: add new apis to iterate bfq entities >>>>>    block, bfq: apply news apis where root group is not expected >>>>>    block, bfq: cleanup for __bfq_activate_requeue_entity() >>>>>    block, bfq: move the increasement of >>>>> 'num_groups_with_pending_reqs' to >>>>>      it's caller >>>>>    block, bfq: count root group into 'num_groups_with_pending_reqs' >>>>>    block, bfq: do not idle if only one cgroup is activated >>>>>    block, bfq: only count parent bfqg when bfqq is activated >>>>>    block, bfq: record how many queues have pending requests in >>>>> bfq_group >>>>>    block, bfq: move forward __bfq_weights_tree_remove() >>>>>    block, bfq: decrease 'num_groups_with_pending_reqs' earlier >>>>>    block, bfq: cleanup bfqq_group() >>>>> >>>>>   block/bfq-cgroup.c  | 13 +++---- >>>>>   block/bfq-iosched.c | 87 >>>>> +++++++++++++++++++++++---------------------- >>>>>   block/bfq-iosched.h | 41 +++++++++++++-------- >>>>>   block/bfq-wf2q.c    | 56 +++++++++++++++-------------- >>>>>   4 files changed, 106 insertions(+), 91 deletions(-) >>>>>