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 AF40BC7EE23 for ; Thu, 11 May 2023 15:19:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238417AbjEKPT3 (ORCPT ); Thu, 11 May 2023 11:19:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237687AbjEKPT1 (ORCPT ); Thu, 11 May 2023 11:19:27 -0400 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C2A7F7; Thu, 11 May 2023 08:19:23 -0700 (PDT) Received: by verein.lst.de (Postfix, from userid 2407) id 6366168D08; Thu, 11 May 2023 17:19:19 +0200 (CEST) Date: Thu, 11 May 2023 17:19:19 +0200 From: Christoph Hellwig To: Yu Kuai Cc: hch@lst.de, tj@kernel.org, josef@toxicpanda.com, axboe@kernel.dk, yukuai3@huawei.com, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com Subject: Re: [PATCH -next 1/6] blk-wbt: fix that wbt can't be disabled by default Message-ID: <20230511151919.GA7880@lst.de> References: <20230511014509.679482-1-yukuai1@huaweicloud.com> <20230511014509.679482-2-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230511014509.679482-2-yukuai1@huaweicloud.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 11, 2023 at 09:45:04AM +0800, Yu Kuai wrote: > @@ -730,8 +730,9 @@ void wbt_enable_default(struct gendisk *disk) > { > struct request_queue *q = disk->queue; > struct rq_qos *rqos; > - bool disable_flag = q->elevator && > - test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags); > + bool disable_flag = (q->elevator && > + test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags)) || > + !IS_ENABLED(CONFIG_BLK_WBT_MQ); Not really new in your patch, but I find the logic here very confusing. First the disable_flag really should be enable instead, as that's how it's actually checked, and then spelling out the conditions a bit more would really help readability. E.g. bool enabled = IS_ENABLED(CONFIG_BLK_WBT_MQ); if (q->elevator && test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags)) enable = false;