From patchwork Wed Jul 26 19:34:07 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: 13328490 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 52BA2C0015E for ; Wed, 26 Jul 2023 19:35:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230095AbjGZTfJ (ORCPT ); Wed, 26 Jul 2023 15:35:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229454AbjGZTfH (ORCPT ); Wed, 26 Jul 2023 15:35:07 -0400 Received: from mail-pf1-f170.google.com (mail-pf1-f170.google.com [209.85.210.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA8BD2D43 for ; Wed, 26 Jul 2023 12:35:05 -0700 (PDT) Received: by mail-pf1-f170.google.com with SMTP id d2e1a72fcca58-686efdeabaeso137156b3a.3 for ; Wed, 26 Jul 2023 12:35:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690400105; x=1691004905; 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=Spi0QoOx8xiu22EDvlyX8nDXg1t+SawetU4mZevhtFk=; b=VYG9TXj7Awes2O8G7wdYPU56BQhlnh1LtLs6PjL3f2DIkxWIpEQnyPkhavL3K7At9I QO2W4/hNUVZiwR5QeGwsDHPh7yQKDef7BnjOBjQ3/Qn8ISP48tSMgtWxstzAxng6Ko1G A+LoPtRE5CQxQhal5kcRquuuW2pRAZbPr/+3EszIxP+q/XYLq0ADo5LJhf6Gk20GEdl0 Z/XvkPxWNOGR6FB86NaIhc3x6ICC1IbAIRXrqaXhVltU6mgnvjsvNEM9tJwtyB9vBQwN UP4bIvSz28JcRIn31mPA18cX2tGFMN3lLg2V/9hpMgLuzHctg4aEA4SJfH4oa1ZV/yco T2IA== X-Gm-Message-State: ABy/qLaaU5udA0nfQBPs2v6ctRPctbksO3ai8UXxWIjZfH4SM9qtcyg9 0RL4HMDHhJnH4oTgIywEgfQ= X-Google-Smtp-Source: APBJJlEMDh1KZg3grPe1Zdftvn5YnV5i/pG6YClz0QeU5WruwdXSJEDm+ZRXS/k/Pap1UZ/83u5p/A== X-Received: by 2002:a05:6a00:181e:b0:686:9385:4644 with SMTP id y30-20020a056a00181e00b0068693854644mr3454388pfa.2.1690400105218; Wed, 26 Jul 2023 12:35:05 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:32d2:d535:b137:7ba3]) by smtp.gmail.com with ESMTPSA id x52-20020a056a000bf400b00682ba300cd1sm11846685pfu.29.2023.07.26.12.35.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Jul 2023 12:35:04 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , "Martin K . Petersen" , Jaegeuk Kim , Damien Le Moal , Bart Van Assche , Ming Lei Subject: [PATCH v4 3/7] block/mq-deadline: Only use zone locking if necessary Date: Wed, 26 Jul 2023 12:34:07 -0700 Message-ID: <20230726193440.1655149-4-bvanassche@acm.org> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog In-Reply-To: <20230726193440.1655149-1-bvanassche@acm.org> References: <20230726193440.1655149-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Measurements have shown that limiting the queue depth to one 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 zoned writes are submitted in order and 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 submits write requests per zone in LBA order. Cc: Christoph Hellwig Cc: Damien Le Moal Cc: Ming Lei Signed-off-by: Bart Van Assche --- block/mq-deadline.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index 02a916ba62ee..9a64577fe942 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -338,6 +338,17 @@ static struct request *deadline_skip_seq_writes(struct deadline_data *dd, return rq; } +/* + * Use write locking if either QUEUE_FLAG_NO_ZONE_WRITE_LOCK or + * REQ_NO_ZONE_WRITE_LOCK has not been set. Not using zone write locking is + * only safe if the submitter allocates and submit requests in LBA order per + * zone and if the block driver preserves the request order. + */ +static bool dd_use_write_locking(struct request *rq) +{ + return blk_queue_is_zoned(rq->q) && !blk_no_zone_write_lock(rq); +} + /* * For the specified data direction, return the next request to * dispatch using arrival ordered lists. @@ -353,7 +364,7 @@ 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_write_locking(rq)) return rq; /* @@ -398,7 +409,7 @@ 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_write_locking(rq)) return rq; /* @@ -526,8 +537,9 @@ 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 +564,8 @@ 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_write_locking(rq)) + blk_req_zone_write_lock(rq); rq->rq_flags |= RQF_STARTED; return rq; } @@ -933,7 +946,7 @@ static void dd_finish_request(struct request *rq) atomic_inc(&per_prio->stats.completed); - if (blk_queue_is_zoned(q)) { + if (dd_use_write_locking(rq)) { unsigned long flags; spin_lock_irqsave(&dd->zone_lock, flags);