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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A644AC7EE2D for ; Wed, 17 May 2023 17:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229883AbjEQRpm (ORCPT ); Wed, 17 May 2023 13:45:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229551AbjEQRph (ORCPT ); Wed, 17 May 2023 13:45:37 -0400 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27133D2D9 for ; Wed, 17 May 2023 10:45:08 -0700 (PDT) Received: by mail-pf1-f177.google.com with SMTP id d2e1a72fcca58-643a1fed360so763052b3a.3 for ; Wed, 17 May 2023 10:45:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684345482; x=1686937482; 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=EtawUDGVkAQQgu3j8B80kzwNBVCXAkTme75c4XUrVi8=; b=CzEEUi5Bs+g1cDFaCgUPnOCxOPRwLu8BFuNj2GyduMAd9z2+Sjx3m9t83XPSydG1+3 1C+FcTtj6Weu891cKnJaEoEm4pEnFWzU5xJfKFbe67YUyZ3FiGi/rtV2VeOemRH+dE7Q IEl0TpBjyYqEoq3ec/EXCi6JAdnl3tZv8V5KkU5QsroJYUOu2+fJAWI/lB4yt1gKlWVT yxDJQdw0OCzJvnwD8YX2lExyTqnKOoh6nTdVbaXyDBy59xBqeeN1okRLyYKUOPm1HznD AD1QyXrXe4WaF4xsCaVhPK6kT09dqzW1lgH/qC+QEA9kMA1dS65ePGBa7yBc2ri4GYjO Zt8Q== X-Gm-Message-State: AC+VfDyJ7VIeu7y+71IHZ7QsdjnumQMplu+/fiav0DTtcfwqzLR+3G2P Kt0aSe+yfw3EyQc7l+ZaLrE= X-Google-Smtp-Source: ACHHUZ6qPwa2ddHDgtreNJt0ieufZE3y3ID1L+uVL8azLa28s6s4BUWUGB9IwtRaXHZn3wTRwjpF+g== X-Received: by 2002:a05:6a00:1a15:b0:64c:c842:5864 with SMTP id g21-20020a056a001a1500b0064cc8425864mr661984pfv.14.1684345481712; Wed, 17 May 2023 10:44:41 -0700 (PDT) Received: from bvanassche-glaptop2.roam.corp.google.com ([98.51.102.78]) by smtp.gmail.com with ESMTPSA id d22-20020aa78e56000000b00646e7d2b5a7sm15334410pfr.112.2023.05.17.10.44.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 May 2023 10:44:41 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Damien Le Moal , Hannes Reinecke , Ming Lei Subject: [PATCH v6 08/11] block: mq-deadline: Reduce lock contention Date: Wed, 17 May 2023 10:42:26 -0700 Message-ID: <20230517174230.897144-9-bvanassche@acm.org> X-Mailer: git-send-email 2.40.1.698.g37aff9b760-goog In-Reply-To: <20230517174230.897144-1-bvanassche@acm.org> References: <20230517174230.897144-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Cc: Ming Lei Signed-off-by: Bart Van Assche --- 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 56782ee93522..44222d18f6d4 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(). */