From patchwork Thu Oct 14 01:45:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12557659 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 591AFC433EF for ; Thu, 14 Oct 2021 01:33:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35259611CA for ; Thu, 14 Oct 2021 01:33:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229877AbhJNBfW (ORCPT ); Wed, 13 Oct 2021 21:35:22 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:14349 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229794AbhJNBfU (ORCPT ); Wed, 13 Oct 2021 21:35:20 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4HVBcR5JPgz908v; Thu, 14 Oct 2021 09:28:23 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.8; Thu, 14 Oct 2021 09:33:14 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Thu, 14 Oct 2021 09:33:14 +0800 From: Yu Kuai To: , CC: , , , Subject: [PATCH v4 1/2] block, bfq: counted root group into 'num_groups_with_pending_reqs' Date: Thu, 14 Oct 2021 09:45:55 +0800 Message-ID: <20211014014556.3597008-2-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211014014556.3597008-1-yukuai3@huawei.com> References: <20211014014556.3597008-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 'num_groups_with_pending_reqs' represents how many groups that are not root group and have pending requests. This patch also counted root group into 'num_groups_with_pending_reqs'. Signed-off-by: Yu Kuai --- block/bfq-iosched.c | 36 ++++++++++++++++++++++++++------ block/bfq-wf2q.c | 50 +++++++++++++++++++++++++++++++++------------ 2 files changed, 67 insertions(+), 19 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index fec18118dc30..d251735383f7 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -852,6 +852,16 @@ void __bfq_weights_tree_remove(struct bfq_data *bfqd, bfq_put_queue(bfqq); } +static inline void +bfq_clear_group_with_pending_reqs(struct bfq_data *bfqd, + struct bfq_entity *entity) +{ + if (entity->in_groups_with_pending_reqs) { + entity->in_groups_with_pending_reqs = false; + bfqd->num_groups_with_pending_reqs--; + } +} + /* * Invoke __bfq_weights_tree_remove on bfqq and decrement the number * of active groups for each queue's inactive parent entity. @@ -860,9 +870,25 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_queue *bfqq) { struct bfq_entity *entity = bfqq->entity.parent; + struct bfq_sched_data *sd; + + /* + * If the bfq queue is in root group, the decrement of + * num_groups_with_pending_reqs is performed immediately upon the + * deactivation of entity. + */ + if (!entity) { + entity = &bfqd->root_group->entity; + sd = entity->my_sched_data; + + if (!sd->in_service_entity) + bfq_clear_group_with_pending_reqs(bfqd, entity); + + return; + } for_each_entity(entity) { - struct bfq_sched_data *sd = entity->my_sched_data; + sd = entity->my_sched_data; if (sd->next_in_service || sd->in_service_entity) { /* @@ -880,7 +906,8 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, } /* - * The decrement of num_groups_with_pending_reqs is + * If the bfq queue is not in root group, + * the decrement of num_groups_with_pending_reqs is * not performed immediately upon the deactivation of * entity, but it is delayed to when it also happens * that the first leaf descendant bfqq of entity gets @@ -889,10 +916,7 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, * needed. See the comments on * num_groups_with_pending_reqs for details. */ - if (entity->in_groups_with_pending_reqs) { - entity->in_groups_with_pending_reqs = false; - bfqd->num_groups_with_pending_reqs--; - } + bfq_clear_group_with_pending_reqs(bfqd, entity); } /* diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index b74cc0da118e..3e9e672aa302 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -945,6 +945,42 @@ static void bfq_update_fin_time_enqueue(struct bfq_entity *entity, bfq_active_insert(st, entity); } +#ifdef CONFIG_BFQ_GROUP_IOSCHED +static inline void +bfq_set_group_with_pending_reqs(struct bfq_data *bfqd, + struct bfq_entity *entity) +{ + if (!entity->in_groups_with_pending_reqs) { + entity->in_groups_with_pending_reqs = true; + bfqd->num_groups_with_pending_reqs++; + } +} + +static void bfq_update_groups_with_pending_reqs(struct bfq_entity *entity) +{ + struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); + + if (bfqq) { + /* + * If the entity represents bfq_queue, and the queue belongs to + * root cgroup. + */ + if (!entity->parent) + bfq_set_group_with_pending_reqs(bfqq->bfqd, + &bfqq->bfqd->root_group->entity); + } else { + /* If the entity represents bfq_group. */ + struct bfq_group *bfqg = + container_of(entity, struct bfq_group, entity); + struct bfq_data *bfqd = bfqg->bfqd; + + bfq_set_group_with_pending_reqs(bfqd, entity); + } +} +#else +#define bfq_update_groups_with_pending_reqs(entity) \ + do {} while (0) +#endif /** * __bfq_activate_entity - handle activation of entity. @@ -999,19 +1035,7 @@ static void __bfq_activate_entity(struct bfq_entity *entity, entity->on_st_or_in_serv = true; } -#ifdef CONFIG_BFQ_GROUP_IOSCHED - if (!bfq_entity_to_bfqq(entity)) { /* bfq_group */ - struct bfq_group *bfqg = - container_of(entity, struct bfq_group, entity); - struct bfq_data *bfqd = bfqg->bfqd; - - if (!entity->in_groups_with_pending_reqs) { - entity->in_groups_with_pending_reqs = true; - bfqd->num_groups_with_pending_reqs++; - } - } -#endif - + bfq_update_groups_with_pending_reqs(entity); bfq_update_fin_time_enqueue(entity, st, backshifted); } From patchwork Thu Oct 14 01:45:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12557661 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37EBEC433F5 for ; Thu, 14 Oct 2021 01:33:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A332611C7 for ; Thu, 14 Oct 2021 01:33:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229794AbhJNBf3 (ORCPT ); Wed, 13 Oct 2021 21:35:29 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:25183 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229904AbhJNBf3 (ORCPT ); Wed, 13 Oct 2021 21:35:29 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4HVBhw0Gf6z8tdH; Thu, 14 Oct 2021 09:32:16 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.8; Thu, 14 Oct 2021 09:33:14 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Thu, 14 Oct 2021 09:33:14 +0800 From: Yu Kuai To: , CC: , , , Subject: [PATCH v4 2/2] block, bfq: do not idle if only one cgroup is activated Date: Thu, 14 Oct 2021 09:45:56 +0800 Message-ID: <20211014014556.3597008-3-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211014014556.3597008-1-yukuai3@huawei.com> References: <20211014014556.3597008-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org If only one group is activated, there is no need to guarantee the same share of the throughput of queues in the same group. Test procedure: run "fio -numjobs=1 -ioengine=psync -bs=4k -direct=1 -rw=randread..." multiple times in the same cgroup. Test result: total bandwidth(Mib/s) | total jobs | before this patch | after this patch | | ---------- | ----------------- | --------------------- | | 1 | 33.8 | 33.8 | | 2 | 33.8 | 65.4 (32.7 each job) | | 4 | 33.8 | 106.8 (26.7 each job) | | 8 | 33.8 | 126.4 (15.8 each job) | By the way, if I test with "fio -numjobs=1/2/4/8 ...", test result is the same with or without this patch. This is because bfq_queue can be merged in this situation. Signed-off-by: Yu Kuai --- block/bfq-iosched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d251735383f7..8d94f511bee8 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -709,7 +709,7 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) * much easier to maintain the needed state: * 1) all active queues have the same weight, * 2) all active queues belong to the same I/O-priority class, - * 3) there are no active groups. + * 3) there are one active group at most. * In particular, the last condition is always true if hierarchical * support or the cgroups interface are not enabled, thus no state * needs to be maintained in this case. @@ -741,7 +741,7 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, return varied_queue_weights || multiple_classes_busy #ifdef CONFIG_BFQ_GROUP_IOSCHED - || bfqd->num_groups_with_pending_reqs > 0 + || bfqd->num_groups_with_pending_reqs > 1 #endif ; }