From patchwork Fri Aug 4 15:48:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 711089 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 707C0C41513 for ; Fri, 4 Aug 2023 15:48:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232125AbjHDPsh (ORCPT ); Fri, 4 Aug 2023 11:48:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232079AbjHDPsc (ORCPT ); Fri, 4 Aug 2023 11:48:32 -0400 Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DAF52D71; Fri, 4 Aug 2023 08:48:31 -0700 (PDT) Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-686f1240a22so2059036b3a.0; Fri, 04 Aug 2023 08:48:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691164110; x=1691768910; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/dgxEXFnorII/KCLaOV4R9mvcBZp+FsMdRey1KII0Yw=; b=ak8HBgVYIjMGaCC5XR/UVRLaOs3pM60VRHsNpZBZ7gBiAvP4oNzAJwP4s8bRs+4trf Bh0YqU8Ss9vbxybGi+6FKNpwEBIuEnCElvaCyExmBNbrxbV3xCC6qpbs4zjmYgAyA+OQ euPs/r9b6pOYL+al9mY0AIk6PXKills9tJj4xLPEorZugVpatQQV5N7BQtT3NW12CgtJ rrJeOY5/aVKKILepNqaDX5j6DmRlq20AbyS6XtdIDOSZCqeYYCZ/BSCpS+YDbdyqnX+y HZ60MzMnYqxjUb8YxH5dSkLRr2D09wmGxRarBxCVqtaHShDOypRKFtMbrrgUEtYZ73Po Rvnw== X-Gm-Message-State: AOJu0YxcJyX7tfNWi+Cd5cfZQvn1RGS8Kut4fw97D5ijyZ/Lkexdakkh ItArraQaYue12k9UFc8scHQ= X-Google-Smtp-Source: AGHT+IFWBWo9WoVkeoqVtei66Au+rXkw/bmznip5BJsQzjlXJa+HYw6p7t4RGUdRjnh+gEap6Ym9pQ== X-Received: by 2002:a05:6a20:6a28:b0:135:293b:9b14 with SMTP id p40-20020a056a206a2800b00135293b9b14mr2587253pzk.55.1691164110488; Fri, 04 Aug 2023 08:48:30 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:4af5:d063:a66d:403b]) by smtp.gmail.com with ESMTPSA id h8-20020a62b408000000b00640ddad2e0dsm1760839pfn.47.2023.08.04.08.48.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Aug 2023 08:48:29 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, "Martin K . Petersen" , Christoph Hellwig , Bart Van Assche , Damien Le Moal , Ming Lei Subject: [PATCH v6 2/7] block/mq-deadline: Only use zone locking if necessary Date: Fri, 4 Aug 2023 08:48:00 -0700 Message-ID: <20230804154821.3232094-3-bvanassche@acm.org> X-Mailer: git-send-email 2.41.0.640.ga95def55d0-goog In-Reply-To: <20230804154821.3232094-1-bvanassche@acm.org> References: <20230804154821.3232094-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Measurements have shown that limiting the queue depth to one per zone for zoned writes has a significant negative performance impact on zoned UFS devices. Hence this patch that disables zone locking by the mq-deadline scheduler if the storage controller preserves the command order. This patch is based on the following assumptions: - It happens infrequently that zoned write requests are reordered by the block layer. - The I/O priority of all write requests is the same per zone. - Either no I/O scheduler is used or an I/O scheduler is used that serializes write requests per zone. Reviewed-by: Damien Le Moal Cc: Christoph Hellwig Cc: Ming Lei Signed-off-by: Bart Van Assche --- block/mq-deadline.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index 02a916ba62ee..1f4124dd4a0b 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -338,6 +338,16 @@ static struct request *deadline_skip_seq_writes(struct deadline_data *dd, return rq; } +/* + * Use write locking if either QUEUE_FLAG_NO_ZONE_WRITE_LOCK has not been set. + * Not using zone write locking is only safe if the block driver preserves the + * request order. + */ +static bool dd_use_zone_write_locking(struct request_queue *q) +{ + return blk_queue_is_zoned(q) && !blk_queue_no_zone_write_lock(q); +} + /* * For the specified data direction, return the next request to * dispatch using arrival ordered lists. @@ -353,7 +363,7 @@ deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio, return NULL; rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next); - if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q)) + if (data_dir == DD_READ || !dd_use_zone_write_locking(rq->q)) return rq; /* @@ -398,7 +408,7 @@ deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio, if (!rq) return NULL; - if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q)) + if (data_dir == DD_READ || !dd_use_zone_write_locking(rq->q)) return rq; /* @@ -526,8 +536,9 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd, } /* - * For a zoned block device, if we only have writes queued and none of - * them can be dispatched, rq will be NULL. + * For a zoned block device that requires write serialization, if we + * only have writes queued and none of them can be dispatched, rq will + * be NULL. */ if (!rq) return NULL; @@ -552,7 +563,8 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd, /* * If the request needs its target zone locked, do it. */ - blk_req_zone_write_lock(rq); + if (dd_use_zone_write_locking(rq->q)) + blk_req_zone_write_lock(rq); rq->rq_flags |= RQF_STARTED; return rq; } @@ -933,7 +945,7 @@ static void dd_finish_request(struct request *rq) atomic_inc(&per_prio->stats.completed); - if (blk_queue_is_zoned(q)) { + if (dd_use_zone_write_locking(rq->q)) { unsigned long flags; spin_lock_irqsave(&dd->zone_lock, flags);