From patchwork Sun Oct 30 10:07:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13025064 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 5E37CFA373D for ; Sun, 30 Oct 2022 10:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230112AbiJ3KHo (ORCPT ); Sun, 30 Oct 2022 06:07:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230102AbiJ3KHo (ORCPT ); Sun, 30 Oct 2022 06:07:44 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E6531F2 for ; Sun, 30 Oct 2022 03:07:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=4c0WdD1P3xzEWKvGeAJDqWeuPkp65sLTQP2bAdYLIy4=; b=vthMF6oKO3m790sDU7+wMXb/fK /+PzWDgFpNdAYP3QFiTAHUKKQXmVwrss0DwK+jLE8iEeQcOiMo0B1Xi4yq+qHsNG7m9KVDQgCVq6B SbNArDL6dm5EE6UsAkLQo7aN7pmhA2HFT/pl2zKVI0lCklz9qd1nGFfibLA0mKY2tgEGasTzwjYNg iv7iYZi2/PVr+7oFaWLkWFNOh4+/C6nLZTR5dkTCBdCzYTEelBAIwLPFLELdNgdqQkZEAVegY3n2t KzJeTW/HBGmY6I2rwrZaqrXhUB6t3gF+Tzwm+5yu7OtNCpspp15LjAJ5GpzZTk1AEUzJhKf1HZUxS rMOTC8/g==; Received: from [2001:4bb8:199:6818:1c2a:5f62:2eb:6092] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1op5EE-00F8SJ-DU; Sun, 30 Oct 2022 10:07:42 +0000 From: Christoph Hellwig To: Jens Axboe Cc: linux-block@vger.kernel.org Subject: [PATCH 7/7] block: split elevator_switch Date: Sun, 30 Oct 2022 11:07:14 +0100 Message-Id: <20221030100714.876891-8-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221030100714.876891-1-hch@lst.de> References: <20221030100714.876891-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Split an elevator_disable helper from elevator_switch for the case where we want to switch to no scheduler at all. This includes removing the pointless elevator_switch_mq helper and removing the switch to no schedule logic from blk_mq_init_sched. Signed-off-by: Christoph Hellwig --- block/blk-mq-sched.c | 7 ---- block/blk-mq.c | 2 +- block/blk.h | 1 + block/elevator.c | 77 ++++++++++++++++++++++---------------------- 4 files changed, 40 insertions(+), 47 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 68227240fdea3..23d1a90fec427 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -564,13 +564,6 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) unsigned long i; int ret; - if (!e) { - blk_queue_flag_clear(QUEUE_FLAG_SQ_SCHED, q); - q->elevator = NULL; - q->nr_requests = q->tag_set->queue_depth; - return 0; - } - /* * Default to double of smaller one between hw queue_depth and 128, * since we don't split into sync/async like the old code did. diff --git a/block/blk-mq.c b/block/blk-mq.c index 4cecf281123f6..1ebb2e68ac66f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4556,7 +4556,7 @@ static bool blk_mq_elv_switch_none(struct list_head *head, __elevator_get(qe->type); qe->type = q->elevator->type; list_add(&qe->node, head); - elevator_switch(q, NULL); + elevator_disable(q); mutex_unlock(&q->sysfs_lock); return true; diff --git a/block/blk.h b/block/blk.h index 7f9e089ab1f75..f1398fb96cec9 100644 --- a/block/blk.h +++ b/block/blk.h @@ -278,6 +278,7 @@ bool blk_bio_list_merge(struct request_queue *q, struct list_head *list, void blk_insert_flush(struct request *rq); int elevator_switch(struct request_queue *q, struct elevator_type *new_e); +void elevator_disable(struct request_queue *q); void elevator_exit(struct request_queue *q); int elv_register_queue(struct request_queue *q, bool uevent); void elv_unregister_queue(struct request_queue *q); diff --git a/block/elevator.c b/block/elevator.c index 4042e524333e0..6fdbfca1bc61e 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -548,39 +548,6 @@ void elv_unregister(struct elevator_type *e) } EXPORT_SYMBOL_GPL(elv_unregister); -static int elevator_switch_mq(struct request_queue *q, - struct elevator_type *new_e) -{ - int ret; - - lockdep_assert_held(&q->sysfs_lock); - - if (q->elevator) { - elv_unregister_queue(q); - elevator_exit(q); - } - - ret = blk_mq_init_sched(q, new_e); - if (ret) - goto out; - - if (new_e) { - ret = elv_register_queue(q, true); - if (ret) { - elevator_exit(q); - goto out; - } - } - - if (new_e) - blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name); - else - blk_add_trace_msg(q, "elv switch: none"); - -out: - return ret; -} - static inline bool elv_support_iosched(struct request_queue *q) { if (!queue_is_mq(q) || @@ -685,19 +652,51 @@ void elevator_init_mq(struct request_queue *q) */ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) { - int err; + int ret; lockdep_assert_held(&q->sysfs_lock); blk_mq_freeze_queue(q); blk_mq_quiesce_queue(q); - err = elevator_switch_mq(q, new_e); + if (q->elevator) { + elv_unregister_queue(q); + elevator_exit(q); + } + ret = blk_mq_init_sched(q, new_e); + if (ret) + goto out_unfreeze; + + ret = elv_register_queue(q, true); + if (ret) { + elevator_exit(q); + goto out_unfreeze; + } + blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name); + +out_unfreeze: blk_mq_unquiesce_queue(q); blk_mq_unfreeze_queue(q); + return ret; +} + +void elevator_disable(struct request_queue *q) +{ + lockdep_assert_held(&q->sysfs_lock); - return err; + blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); + + elv_unregister_queue(q); + elevator_exit(q); + blk_queue_flag_clear(QUEUE_FLAG_SQ_SCHED, q); + q->elevator = NULL; + q->nr_requests = q->tag_set->queue_depth; + blk_add_trace_msg(q, "elv switch: none"); + + blk_mq_unquiesce_queue(q); + blk_mq_unfreeze_queue(q); } /* @@ -716,9 +715,9 @@ static int elevator_change(struct request_queue *q, const char *elevator_name) * Special case for mq, turn off scheduling */ if (!strncmp(elevator_name, "none", 4)) { - if (!q->elevator) - return 0; - return elevator_switch(q, NULL); + if (q->elevator) + elevator_disable(q); + return 0; } if (q->elevator && elevator_match(q->elevator->type, elevator_name))