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 B0462C433F5 for ; Thu, 17 Mar 2022 01:49:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358362AbiCQBuh (ORCPT ); Wed, 16 Mar 2022 21:50:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348344AbiCQBug (ORCPT ); Wed, 16 Mar 2022 21:50:36 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9313115A00; Wed, 16 Mar 2022 18:49:20 -0700 (PDT) Received: from kwepemi100026.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KJqgl4t78zcb2M; Thu, 17 Mar 2022 09:44:19 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi100026.china.huawei.com (7.221.188.60) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 17 Mar 2022 09:49:18 +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; Thu, 17 Mar 2022 09:49:17 +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> Message-ID: <11fda851-a552-97ea-d083-d0288c17ba53@huawei.com> Date: Thu, 17 Mar 2022 09:49:16 +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: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.73] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-) >>