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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EF0EC433F5 for ; Tue, 19 Oct 2021 17:00:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 622906113B for ; Tue, 19 Oct 2021 17:00:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234038AbhJSRDF (ORCPT ); Tue, 19 Oct 2021 13:03:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230158AbhJSRDF (ORCPT ); Tue, 19 Oct 2021 13:03:05 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F4D5C06161C; Tue, 19 Oct 2021 10:00:52 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id e5-20020a17090a804500b001a116ad95caso382404pjw.2; Tue, 19 Oct 2021 10:00:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=5oDh6wY5mxgjBgRFmj6OpdKqeAcazi57fngXpPsPLWE=; b=lRts9Q2QN5BocnpFjJPqpBK3Fxaxv4kEBoF/rHLBeWaGIYwAxlKsPIhkQCB7sNAmRj UERoxRYtgRGMzur8k2GM5Y/uFfigfGYqd1hcqOryGHOglz1dxWtZNVUYhgx0tD+hilKq V8/oWKqn3J2sTUprRMG/t7pLpLgbMEIoyy/+Yyr6FKU3FUd/0I1Urd0FLCulQCkhKyz8 4TLlu7kFoFyRAEOHLSuV4dkq9oUAiIfZuvxmu4RCbRc28MpW7etPuuxUZLeetNOmIejx 9MpRHH231nr3EYgiUBiOpX+2Z1SpFRYcJy86zemrDgVuzLz5/JQWebAYxJqNe4SaNEB/ rBww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=5oDh6wY5mxgjBgRFmj6OpdKqeAcazi57fngXpPsPLWE=; b=j+/sT10d7Kmyk1NLXKKnjsj1T7gQ/gSjhAEZOG/oNP/KWILgAsbWR+8hmypzvQGScz 0nDq6oQfxT1r/qkz34+jqTk1IGaL0ActKV5pYnYdjMQhFUeFP9C50WEav3jDvzPetlSw z4OiwZ6xY0v6fGZ+sHEtcDj6fU8Uhrp4bnbCIbcvihoOOs45KTlYvRLynlMtezOuYp/w r1bjoCiE13EX68qggPPqC0qO2DBw4mxldSQD1mAUxszaI+n0kziYJP9FIsURqBzil/Z4 0GWaU2N3/o4C3tG8ceZ55X4W0HMOA1W0maI9DxSwjPd3LpY7ELJw5MR+NLiA4nHqUTo+ m5qg== X-Gm-Message-State: AOAM532A4F/NOZujYTYIdskqkXkb1HYdN4grMr+PRWvyvcKFHh4cuoT6 F9LEjn4Pa1IwADd1Q9NsSvRtdy27rn4BYw== X-Google-Smtp-Source: ABdhPJz2Txw4Iyq0OpTfOKDWQ5EPgZrJEgJ5wmiLGj6rOynX5rPquD2dOQEYI7PZZR0bLUwKgFAVJg== X-Received: by 2002:a17:902:c942:b0:13f:d1c:819a with SMTP id i2-20020a170902c94200b0013f0d1c819amr34461656pla.64.1634662851444; Tue, 19 Oct 2021 10:00:51 -0700 (PDT) Received: from localhost (2603-800c-1a02-1bae-e24f-43ff-fee6-449f.res6.spectrum.com. [2603:800c:1a02:1bae:e24f:43ff:fee6:449f]) by smtp.gmail.com with ESMTPSA id i123sm16894060pfg.157.2021.10.19.10.00.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Oct 2021 10:00:50 -0700 (PDT) Sender: Tejun Heo Date: Tue, 19 Oct 2021 07:00:49 -1000 From: Tejun Heo To: Yu Kuai Cc: axboe@kernel.dk, paolo.valente@linaro.org, avanzini.arianna@gmail.com, fchecconi@gmail.com, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com Subject: Re: [PATCH v3 -next 1/2] blk-cgroup: don't call blk_mq_freeze_queue() in blkcg_deactivate_policy() Message-ID: References: <20211019024132.432458-1-yukuai3@huawei.com> <20211019024132.432458-2-yukuai3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211019024132.432458-2-yukuai3@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, On Tue, Oct 19, 2021 at 10:41:31AM +0800, Yu Kuai wrote: > blkcg_deactivate_policy() can be called from either > blk_cleanup_queue() for all policies or elevator_switch() for bfq > policy. Thus there is no need to freeze queue in > blkcg_deactivate_policy() since the caller freeze the queue aready. > > Signed-off-by: Yu Kuai I would just keep the calls. The operation requires the q to be frozen and there isn't a good way to annotate that the caller must be holding a usage count, so it's useful even just as documentation. Thanks. -- tejun