From patchwork Wed Jul 14 09:45:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12376417 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F01B3C11F66 for ; Wed, 14 Jul 2021 09:37:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DC24D61073 for ; Wed, 14 Jul 2021 09:37:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238933AbhGNJkN (ORCPT ); Wed, 14 Jul 2021 05:40:13 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:6817 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238841AbhGNJkI (ORCPT ); Wed, 14 Jul 2021 05:40:08 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GPshT5WPjzXswM; Wed, 14 Jul 2021 17:31:37 +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 15.1.2176.2; Wed, 14 Jul 2021 17:37:15 +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 15.1.2176.2; Wed, 14 Jul 2021 17:37:15 +0800 From: Yu Kuai To: , CC: , , , Subject: [PATCH 1/3] block, bfq: do not idle if only one cgroup is activated Date: Wed, 14 Jul 2021 17:45:27 +0800 Message-ID: <20210714094529.758808-2-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210714094529.758808-1-yukuai3@huawei.com> References: <20210714094529.758808-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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, specifically 'bfqd->num_groups_with_pending_reqs == 1', there is no need to guarantee the same share of the throughput of queues in the same group. Thus change the condition from '> 0' to '> 1' in bfq_asymmetric_scenario(). By the way, if 'num_groups_with_pending_reqs' is greater than 1, there is no need to check 'varied_queue_weights' and 'multiple_classes_busy', thus move the judgement forward. Test procedure: run "fio -numjobs=1 -ioengine=psync -bs=4k -direct=1 -rw=randread..." multiple times in the same cgroup(not root). 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. Signed-off-by: Yu Kuai --- block/bfq-iosched.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 727955918563..2768a4c1cc45 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -709,7 +709,9 @@ 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 is one active group at most. + * If the last condition is false, there is no need to guarantee the + * same share of the throughput of queues in the same group. * 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. @@ -717,7 +719,16 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, struct bfq_queue *bfqq) { - bool smallest_weight = bfqq && + bool smallest_weight; + bool varied_queue_weights; + bool multiple_classes_busy; + +#ifdef CONFIG_BFQ_GROUP_IOSCHED + if (bfqd->num_groups_with_pending_reqs > 1) + return true; +#endif + + smallest_weight = bfqq && bfqq->weight_counter && bfqq->weight_counter == container_of( @@ -729,21 +740,17 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, * For queue weights to differ, queue_weights_tree must contain * at least two nodes. */ - bool varied_queue_weights = !smallest_weight && + varied_queue_weights = !smallest_weight && !RB_EMPTY_ROOT(&bfqd->queue_weights_tree.rb_root) && (bfqd->queue_weights_tree.rb_root.rb_node->rb_left || bfqd->queue_weights_tree.rb_root.rb_node->rb_right); - bool multiple_classes_busy = + multiple_classes_busy = (bfqd->busy_queues[0] && bfqd->busy_queues[1]) || (bfqd->busy_queues[0] && bfqd->busy_queues[2]) || (bfqd->busy_queues[1] && bfqd->busy_queues[2]); - return varied_queue_weights || multiple_classes_busy -#ifdef CONFIG_BFQ_GROUP_IOSCHED - || bfqd->num_groups_with_pending_reqs > 0 -#endif - ; + return varied_queue_weights || multiple_classes_busy; } /* From patchwork Wed Jul 14 09:45:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12376413 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88EACC07E9A for ; Wed, 14 Jul 2021 09:37:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73E5B61396 for ; Wed, 14 Jul 2021 09:37:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238906AbhGNJkN (ORCPT ); Wed, 14 Jul 2021 05:40:13 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:11413 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238860AbhGNJkI (ORCPT ); Wed, 14 Jul 2021 05:40:08 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GPslB5QtfzccyK; Wed, 14 Jul 2021 17:33:58 +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 15.1.2176.2; Wed, 14 Jul 2021 17:37:16 +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 15.1.2176.2; Wed, 14 Jul 2021 17:37:15 +0800 From: Yu Kuai To: , CC: , , , Subject: [PATCH 2/3] block, bfq: add support to record request size information Date: Wed, 14 Jul 2021 17:45:28 +0800 Message-ID: <20210714094529.758808-3-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210714094529.758808-1-yukuai3@huawei.com> References: <20210714094529.758808-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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 bfq keep dispatching requests with same size, the following information are stored if CONFIG_BFQ_GROUP_IOSCHED is enabled: 1) the size 2) the count of requests 3) when the first request was dispatched These will be used in later patch to support concurrent sync io in such situation. Signed-off-by: Yu Kuai --- block/bfq-iosched.c | 15 +++++++++++++++ block/bfq-iosched.h | 16 ++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 2768a4c1cc45..e5a1093ec30a 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4920,6 +4920,20 @@ static bool bfq_has_work(struct blk_mq_hw_ctx *hctx) bfq_tot_busy_queues(bfqd) > 0; } +static void bfq_update_dispatch_size_info(struct bfq_data *bfqd, + unsigned int size) +{ +#ifdef CONFIG_BFQ_GROUP_IOSCHED + if (bfqd->dispatch_size == size) { + bfqd->dispatch_count++; + } else { + bfqd->dispatch_size = size; + bfqd->dispatch_count = 1; + bfqd->dispatch_time = jiffies; + } +#endif +} + static struct request *__bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) { struct bfq_data *bfqd = hctx->queue->elevator->elevator_data; @@ -5003,6 +5017,7 @@ static struct request *__bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) bfqd->rq_in_driver++; start_rq: rq->rq_flags |= RQF_STARTED; + bfq_update_dispatch_size_info(bfqd, blk_rq_bytes(rq)); } exit: return rq; diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 99c2a3cb081e..4b9d95447a50 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -768,6 +768,22 @@ struct bfq_data { * function) */ unsigned int word_depths[2][2]; + +#ifdef CONFIG_BFQ_GROUP_IOSCHED + /* the size of last dispatched request */ + unsigned int dispatch_size; + /* + * If bfq keep dispatching requests with same size, this store the + * count of requests. We use unsigned long here, so we don't care + * about overflow. + */ + unsigned long dispatch_count; + /* + * If bfq keep dispatching requests with same size, this store the + * time when the first request was dispatched. + */ + unsigned long dispatch_time; +#endif }; enum bfqq_state_flags { From patchwork Wed Jul 14 09:45:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12376415 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30FB4C11F68 for ; Wed, 14 Jul 2021 09:37:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 116AB6120A for ; Wed, 14 Jul 2021 09:37:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238840AbhGNJkO (ORCPT ); Wed, 14 Jul 2021 05:40:14 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:11414 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238866AbhGNJkJ (ORCPT ); Wed, 14 Jul 2021 05:40:09 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GPslC2yGkzcdKD; Wed, 14 Jul 2021 17:33:59 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Wed, 14 Jul 2021 17:37:16 +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 15.1.2176.2; Wed, 14 Jul 2021 17:37:16 +0800 From: Yu Kuai To: , CC: , , , Subject: [PATCH 3/3] block, bfq: consider request size in bfq_asymmetric_scenario() Date: Wed, 14 Jul 2021 17:45:29 +0800 Message-ID: <20210714094529.758808-4-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210714094529.758808-1-yukuai3@huawei.com> References: <20210714094529.758808-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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 There is a special case when bfq do not need to idle when more than one groups is active: 1) all active queues have the same weight, 2) all active queues have the same request size. 3) all active queues belong to the same I/O-priority class, Each time a request is dispatched, bfq can switch in service queue safely, since the throughput of each active queue is guaranteed to be equivalent. Test procedure: run "fio -numjobs=1 -ioengine=psync -bs=4k -direct=1 -rw=randread..." in different cgroup(not root). 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) | Signed-off-by: Yu Kuai --- block/bfq-iosched.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index e5a1093ec30a..b78fe8a1537e 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -268,6 +268,15 @@ static struct kmem_cache *bfq_pool; */ #define BFQ_RATE_SHIFT 16 +/* + * 1) bfq keep dispatching requests with same size for at least one second. + * 2) bfq dispatch at lease 1024 requests + * + * We think bfq are dispatching request with same size if the above two + * conditions hold true. + */ +#define VARIED_REQUEST_SIZE(bfqd) ((bfqd)->dispatch_count < 1024 ||\ + time_before(jiffies, (bfqd)->dispatch_time + HZ)) /* * When configured for computing the duration of the weight-raising * for interactive queues automatically (see the comments at the @@ -724,7 +733,8 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, bool multiple_classes_busy; #ifdef CONFIG_BFQ_GROUP_IOSCHED - if (bfqd->num_groups_with_pending_reqs > 1) + if (bfqd->num_groups_with_pending_reqs > 1 && + VARIED_REQUEST_SIZE(bfqd)) return true; #endif