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 X-Spam-Level: X-Spam-Status: No, score=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 AD84AC433ED for ; Fri, 7 May 2021 10:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73EAE61451 for ; Fri, 7 May 2021 10:16:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235817AbhEGKRC (ORCPT ); Fri, 7 May 2021 06:17:02 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3039 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229812AbhEGKRB (ORCPT ); Fri, 7 May 2021 06:17:01 -0400 Received: from fraeml713-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Fc5jh2Bw7z71ffb; Fri, 7 May 2021 18:07:52 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml713-chm.china.huawei.com (10.206.15.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 7 May 2021 12:15:58 +0200 Received: from [10.47.82.108] (10.47.82.108) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 7 May 2021 11:15:57 +0100 Subject: Re: [PATCH] blk-mq: Use request queue-wide tags for tagset-wide sbitmap To: Ming Lei CC: "axboe@kernel.dk" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "kashyap.desai@broadcom.com" , "chenxiang (M)" , "yama@redhat.com" References: <1620037333-2495-1-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: <4d5893e2-13f0-ce6f-4fd7-44c7ecf8553f@huawei.com> Date: Fri, 7 May 2021 11:15:28 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.82.108] X-ClientProxiedBy: lhreml719-chm.china.huawei.com (10.201.108.70) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 06/05/2021 09:32, Ming Lei wrote: >> + if (blk_mq_is_sbitmap_shared(q->tag_set->flags)) { >> + ret = blk_mq_init_sched_shared_sbitmap(q); >> + if (ret) >> + goto err_free_tags; >> + >> + queue_for_each_hw_ctx(q, hctx, i) { >> + hctx->sched_tags->bitmap_tags = >> + q->sched_bitmap_tags; >> + hctx->sched_tags->breserved_tags = >> + q->sched_breserved_tags; >> + } >> } >> >> ret = e->ops.init_sched(q, e); >> if (ret) >> - goto err; >> + goto err_free_sbitmap; >> >> blk_mq_debugfs_register_sched(q); >> >> @@ -584,6 +590,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) >> eq = q->elevator; >> blk_mq_sched_free_requests(q); >> blk_mq_exit_sched(q, eq); >> + blk_mq_exit_sched_shared_sbitmap(q); > blk_mq_exit_sched_shared_sbitmap() has been called in blk_mq_exit_sched() already. ah, yes > >> kobject_put(&eq->kobj); >> return ret; >> } >> @@ -593,7 +600,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) >> >> return 0; >> >> -err: >> +err_free_sbitmap: >> + if (blk_mq_is_sbitmap_shared(q->tag_set->flags)) >> + blk_mq_exit_sched_shared_sbitmap(q); >> +err_free_tags: >> blk_mq_sched_free_requests(q); >> blk_mq_sched_tags_teardown(q); >> q->elevator = NULL; >> @@ -631,5 +641,7 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) >> if (e->type->ops.exit_sched) >> e->type->ops.exit_sched(e); >> blk_mq_sched_tags_teardown(q); >> + if (blk_mq_is_sbitmap_shared(q->tag_set->flags)) >> + blk_mq_exit_sched_shared_sbitmap(q); >> q->elevator = NULL; >> } >> diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c >> index 2a37731e8244..734fedceca7d 100644 >> --- a/block/blk-mq-tag.c >> +++ b/block/blk-mq-tag.c >> @@ -466,19 +466,40 @@ static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, >> return -ENOMEM; >> } >> >> -int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int flags) >> +static int __blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags, >> + struct sbitmap_queue *breserved_tags, >> + struct blk_mq_tag_set *set, >> + unsigned int queue_depth, >> + unsigned int reserved) >> { >> - unsigned int depth = set->queue_depth - set->reserved_tags; >> + unsigned int depth = queue_depth - reserved; >> int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags); >> bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR; >> - int i, node = set->numa_node; >> >> - if (bt_alloc(&set->__bitmap_tags, depth, round_robin, node)) >> + if (bt_alloc(bitmap_tags, depth, round_robin, set->numa_node)) >> return -ENOMEM; >> - if (bt_alloc(&set->__breserved_tags, set->reserved_tags, >> - round_robin, node)) >> + if (bt_alloc(breserved_tags, set->reserved_tags, >> + round_robin, set->numa_node)) >> goto free_bitmap_tags; >> >> + return 0; >> + >> +free_bitmap_tags: >> + sbitmap_queue_free(bitmap_tags); >> + return -ENOMEM; >> +} >> + >> +int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set) > IMO, this function should be named as blk_mq_init_shared_tags > and moved to blk-mq-sched.c But this is for regular tags. I assume you mean blk_mq_init_sched_shared_sbitmap(), below. If so, I can relocate it. As for "sbitmap" vs "tags" in the name, I'm just being consistent between preexisting blk_mq_init_shared_sbitmap() and blk_mq_sbitmap_shared(), and new blk_mq_init_sched_shared_sbitmap() > >> +{ >> + int i, ret; >> + >> + ret = __blk_mq_init_bitmaps(&set->__bitmap_tags, >> + &set->__breserved_tags, >> + set, set->queue_depth, >> + set->reserved_tags); >> + if (ret) >> + return ret; >> + >> for (i = 0; i < set->nr_hw_queues; i++) { >> struct blk_mq_tags *tags = set->tags[i]; >> >> @@ -487,9 +508,6 @@ int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int flags) >> } >> >> return 0; >> -free_bitmap_tags: >> - sbitmap_queue_free(&set->__bitmap_tags); >> - return -ENOMEM; >> } >> >> void blk_mq_exit_shared_sbitmap(struct blk_mq_tag_set *set) >> @@ -498,6 +516,52 @@ void blk_mq_exit_shared_sbitmap(struct blk_mq_tag_set *set) >> sbitmap_queue_free(&set->__breserved_tags); >> } >> >> +#define MAX_SCHED_RQ (16 * BLKDEV_MAX_RQ) >> + >> +int blk_mq_init_sched_shared_sbitmap(struct request_queue *queue) >> +{ >> + struct blk_mq_tag_set *set = queue->tag_set; >> + int ret; >> + >> + queue->sched_bitmap_tags = >> + kmalloc(sizeof(*queue->sched_bitmap_tags), GFP_KERNEL); >> + queue->sched_breserved_tags = >> + kmalloc(sizeof(*queue->sched_breserved_tags), GFP_KERNEL); >> + if (!queue->sched_bitmap_tags || !queue->sched_breserved_tags) >> + goto err; > The two sbitmap queues can be embedded into 'request queue', so that > we can avoid to re-allocation in every elevator switch. ok > > I will ask Yanhui to test the patch and see if it can make a difference. Thanks