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 B01EDC43461 for ; Wed, 12 May 2021 14:12:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C6EC6127A for ; Wed, 12 May 2021 14:12:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230401AbhELOOF (ORCPT ); Wed, 12 May 2021 10:14:05 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3067 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230196AbhELOOC (ORCPT ); Wed, 12 May 2021 10:14:02 -0400 Received: from fraeml735-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FgGkT5k4Cz6wj4N; Wed, 12 May 2021 22:04:33 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml735-chm.china.huawei.com (10.206.15.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 12 May 2021 16:12:46 +0200 Received: from [10.47.85.216] (10.47.85.216) 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; Wed, 12 May 2021 15:12:45 +0100 Subject: Re: [PATCH v2] 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" , "dgilbert@interlog.com" References: <1620749743-36000-1-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: <06b5ab3f-467a-44eb-c997-5a85508dbcda@huawei.com> Date: Wed, 12 May 2021 15:12:01 +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: [10.47.85.216] X-ClientProxiedBy: lhreml740-chm.china.huawei.com (10.201.108.190) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> >> +static int blk_mq_init_sched_shared_sbitmap(struct request_queue *queue) >> +{ >> + struct blk_mq_tag_set *set = queue->tag_set; >> + int ret; >> + >> + /* >> + * Set initial depth at max so that we don't need to reallocate for >> + * updating nr_requests. >> + */ >> + ret = blk_mq_init_bitmaps(&queue->sched_bitmap_tags, >> + &queue->sched_breserved_tags, >> + set, MAX_SCHED_RQ, set->reserved_tags); >> + if (ret) >> + return ret; >> + >> + sbitmap_queue_resize(&queue->sched_bitmap_tags, >> + queue->nr_requests - set->reserved_tags); >> + >> + return 0; >> +} >> + >> +static void blk_mq_exit_sched_shared_sbitmap(struct request_queue *queue) >> +{ >> + sbitmap_queue_free(&queue->sched_bitmap_tags); >> + sbitmap_queue_free(&queue->sched_breserved_tags); >> +} >> + >> int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) >> { >> struct blk_mq_hw_ctx *hctx; >> @@ -578,12 +598,25 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) >> queue_for_each_hw_ctx(q, hctx, i) { >> ret = blk_mq_sched_alloc_tags(q, hctx, i); >> if (ret) >> - goto err; >> + goto err_free_tags; >> + } >> + >> + 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; >> + } > The above assignment can be folded into blk_mq_init_sched_shared_sbitmap(). > ok >> } >> >> ret = e->ops.init_sched(q, e); >> if (ret) >> - goto err; >> + goto err_free_sbitmap; >> >> blk_mq_debugfs_register_sched(q); >> >> @@ -603,7 +636,10 @@ 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; >> @@ -641,5 +677,7 @@ 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); > The above two lines can be moved to blk_mq_sched_tags_teardown(). blk_mq_sched_tags_teardown() is also used in blk_mq_init_sched() to undo the blk_mq_sched_alloc_tags() calls; however, in that same function we call blk_mq_sched_alloc_tags() and blk_mq_init_sched_shared_sbitmap() separately, so can't combine into a single teardown function. > >> q->elevator = NULL; >> } >> diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h >> index 5b18ab915c65..aff037cfd8e7 100644 >> --- a/block/blk-mq-sched.h >> +++ b/block/blk-mq-sched.h >> @@ -5,6 +5,8 @@ >> #include "blk-mq.h" >> #include "blk-mq-tag.h" >> >> +#define MAX_SCHED_RQ (16 * BLKDEV_MAX_RQ) >> + >> void blk_mq_sched_assign_ioc(struct request *rq); >> >> bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, >> diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c >> index 2a37731e8244..e3ab8631be22 100644 >> --- a/block/blk-mq-tag.c >> +++ b/block/blk-mq-tag.c >> @@ -13,6 +13,7 @@ >> #include >> #include "blk.h" >> #include "blk-mq.h" >> +#include "blk-mq-sched.h" >> #include "blk-mq-tag.h" >> >> /* >> @@ -466,19 +467,39 @@ 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) >> +int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags, >> + struct sbitmap_queue *breserved_tags, >> + struct blk_mq_tag_set *set, > The 'set' parameter can be killed, meantime pass 'node' & 'alloc_policy', > just like blk_mq_init_bitmap_tags()'s type, then blk_mq_init_bitmaps() > can be re-used by blk_mq_init_bitmap_tags() for avoiding to duplicate > bitmap allocation code. I was thinking that we could consolidate here, so let me check this. > >> + 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, > s/set->reserved_tags/reserved/ ok Thanks!