From patchwork Tue May 16 22:33:17 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: 13243947 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 6C39CC77B7A for ; Tue, 16 May 2023 22:33:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229514AbjEPWdn (ORCPT ); Tue, 16 May 2023 18:33:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230060AbjEPWdl (ORCPT ); Tue, 16 May 2023 18:33:41 -0400 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADB056A65 for ; Tue, 16 May 2023 15:33:38 -0700 (PDT) Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-1aaea43def7so1537475ad.2 for ; Tue, 16 May 2023 15:33:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684276418; x=1686868418; 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=rWu1E1H6Cpdlf2SWVyhyPtFI9G5HnS2JOK38qbcbgYY=; b=ex+BpXksq0QY1ruGhKGgJTWymOBq8soCZvbTakCUVGV1WScmUrMaZYaqnYfbgxG4Sr vJiyQpuVi3x8Fso+ocR74KnQQEjQorZ9rfixdKGgJipDxxq7nGxL/+8S67uSTBp4Jex2 utDm7GmgglrFYlf2B7VZ81OK4RJCGHOrJNkApO89giDQOzADFHofjC6w1kvLbYcyHCG+ puDq/D3GJ1qzrnB5BX8YwuKZtnAqVFwftVm+Ug/HFyO8rDqlMbPZWSkrZzkmj0bxPlFF bU408ZYGHBvJHPhGpEUvoMleS8W3LsBE1LhvrR3peMVnM4U5qbiAxoQOJKxKEWSPvmlD UtKg== X-Gm-Message-State: AC+VfDzuOt6GV5I6oENyvJ4x92+XFvbMM1vRmsqV7WUx9xPVRiWIidTw UltoGRz3BWimaZAARgqD/1Y= X-Google-Smtp-Source: ACHHUZ7Oh30UsGrpN3NnHKeJJtybQz++TD/j54NVFPNAviNpaYUvGgRMCgHNl7NERedEgR1UOz08jw== X-Received: by 2002:a17:902:bf4b:b0:1ae:29a8:d6d0 with SMTP id u11-20020a170902bf4b00b001ae29a8d6d0mr4984037pls.59.1684276417952; Tue, 16 May 2023 15:33:37 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:baed:ee38:35e4:f97d]) by smtp.gmail.com with ESMTPSA id d8-20020a170902654800b001ae48d441desm839255pln.148.2023.05.16.15.33.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 May 2023 15:33:37 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Jaegeuk Kim , Christoph Hellwig , Bart Van Assche , Damien Le Moal , Ming Lei Subject: [PATCH v5 08/11] block: mq-deadline: Reduce lock contention Date: Tue, 16 May 2023 15:33:17 -0700 Message-ID: <20230516223323.1383342-9-bvanassche@acm.org> X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog In-Reply-To: <20230516223323.1383342-1-bvanassche@acm.org> References: <20230516223323.1383342-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org blk_mq_free_requests() calls dd_finish_request() indirectly. Prevent nested locking of dd->lock and dd->zone_lock by moving the code for freeing requests. Cc: Damien Le Moal Cc: Christoph Hellwig Cc: Ming Lei Signed-off-by: Bart Van Assche Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke --- block/mq-deadline.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index dbc0feca963e..06af9c28a3bf 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -757,7 +757,7 @@ static bool dd_bio_merge(struct request_queue *q, struct bio *bio, * add rq to rbtree and fifo */ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, - blk_insert_t flags) + blk_insert_t flags, struct list_head *free) { struct request_queue *q = hctx->queue; struct deadline_data *dd = q->elevator->elevator_data; @@ -766,7 +766,6 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio); struct dd_per_prio *per_prio; enum dd_prio prio; - LIST_HEAD(free); lockdep_assert_held(&dd->lock); @@ -783,10 +782,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, rq->elv.priv[0] = (void *)(uintptr_t)1; } - if (blk_mq_sched_try_insert_merge(q, rq, &free)) { - blk_mq_free_requests(&free); + if (blk_mq_sched_try_insert_merge(q, rq, free)) return; - } trace_block_rq_insert(rq); @@ -819,6 +816,7 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, { struct request_queue *q = hctx->queue; struct deadline_data *dd = q->elevator->elevator_data; + LIST_HEAD(free); spin_lock(&dd->lock); while (!list_empty(list)) { @@ -826,9 +824,11 @@ static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, rq = list_first_entry(list, struct request, queuelist); list_del_init(&rq->queuelist); - dd_insert_request(hctx, rq, flags); + dd_insert_request(hctx, rq, flags, &free); } spin_unlock(&dd->lock); + + blk_mq_free_requests(&free); } /* Callback from inside blk_mq_rq_ctx_init(). */