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 A87FDC433F5 for ; Tue, 19 Oct 2021 17:03:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F9916113B for ; Tue, 19 Oct 2021 17:03:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234192AbhJSRFa (ORCPT ); Tue, 19 Oct 2021 13:05:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230158AbhJSRF2 (ORCPT ); Tue, 19 Oct 2021 13:05:28 -0400 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19DB9C06161C; Tue, 19 Oct 2021 10:03:16 -0700 (PDT) Received: by mail-pl1-x636.google.com with SMTP id v20so14101036plo.7; Tue, 19 Oct 2021 10:03:16 -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=cb9GiFttJIShHLaHyamc/d4toGTaUJ3k9crbveF7gg0=; b=BOmxdUfCMIyD2fZr8/EH5QtzCVoYpqEgfRrF3aH/hGloS6T1vl6Tdvj6YFM6KkUavy RiUXbbMRJjlY/7JW6N+rgYfOaijFtrV2a2N5RWQjGjYI85VTkaXw4F6dEJMh/rwPnErE 9QvDSK3qqn5jZQmbFWAY01uZ8ra8GZSHVmcG88sibvQ4RKTsqXh8NXIegJhSOCJ96AsF Vno+Bp3O5ZCNCbjIws4ckNImT7MTuDSOuciaJjDvQf91B2i9lFqT1X4AItb1f1dlFh6m cHO+YPJKuZP4eSgU0q6J694zr7qbycHQ+3esEoDmKGhX7LfHVRQP9bFkEsGD61GBLbS7 QdNQ== 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=cb9GiFttJIShHLaHyamc/d4toGTaUJ3k9crbveF7gg0=; b=ETgsbm93EFGKz6m3nPxdnQ2muuEV+HZi4u2PS3aCExetrPgc7NvAV3GLy5fjuEjSGe Vv7CLTLvdK5MMpcQ7JZ3C+SFzc0c/5I3GmZYTkYpXgYl+fGPTCHdd1fdmyPcXiOSb5z7 u4D7Q62CzVxQLvv9Z2mNvUQaE0Sdp1Mhjbabh0hRRtH1WZi4couG4P1Nqhwgp+l2qoEd NQuBVbx6ehJCwRnFstVG1j7tc52Xxyn+Gd86zPJic7CZCNFM/qHv2of5un8Sh/72j/MI HzYPCcSjovZUrDdLaQ5esC36mGUcRIzLSMPoH1J/wsBwN6WHrpO45TlwUy8++mRgSKYd mbuw== X-Gm-Message-State: AOAM531HOi9HqoaVYQ+jcVOteokmCez2h6DIDuW4JAkHhGmIUB8g12CQ 4Qes99WWhvZlNpB7m8BJVYQ= X-Google-Smtp-Source: ABdhPJz66mdTpBEd9DTd8aqGMXjA5dOYLLbqdtqrA/PRHKQ6nTHF2vOhfbwm/tGwEIFakJGrtN1MaQ== X-Received: by 2002:a17:90a:e64a:: with SMTP id ep10mr1219201pjb.124.1634662995400; Tue, 19 Oct 2021 10:03:15 -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 c9sm15935346pgq.58.2021.10.19.10.03.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Oct 2021 10:03:14 -0700 (PDT) Sender: Tejun Heo Date: Tue, 19 Oct 2021 07:03:13 -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 2/2] blk-cgroup: synchoronize blkg creation against policy deactivation Message-ID: References: <20211019024132.432458-1-yukuai3@huawei.com> <20211019024132.432458-3-yukuai3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211019024132.432458-3-yukuai3@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Some nitpicks. On Tue, Oct 19, 2021 at 10:41:32AM +0800, Yu Kuai wrote: ... > Because blkcg_deactivate_policy() require queue to be freezed, thus grab ^ ^ ^ requires frozen we can grab > q_usage_counter to synchoronize blkg_conf_prep() against > blkcg_deactivate_policy(). ... > + /* > + * blkcg_deactivate_policy() require queue to be freezed, thus grab > + * q_usage_counter to prevent concurrent with blkcg_deactivate_policy(). > + */ Same here. Looks good otherwise. Please feel free to add Acked-by: Tejun Heo Thanks. -- tejun