From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794326808; b=2HsUQNEBJAehoOmYckb7VWjrbL2cgLVfe7TKNgLxvrpsHfZKFahz1P1TCOGBmk476wgS 9HpICSGbYSEJi+3LwhuSKoC9rQ4lmrFb18wDJAAFGh7njoCtGig031YaKz4kj6n4ndG8D HZFB55we2FF2D9beoZaDFZL4aLcXVkApD5HdGHPl74t+Kd8w5V27QCT3YBO49TGbsK8eG 0IEwQeVVn7E8SBnaDeL92Rpx6o6N9BUM6lYiVWu7AlZUDpnRqOWy8C5eB8LsgOpVx61em wqhdLD6TC6AMN25Cv7SXop+8U2jWclylNL/sztwEupdXh4VNzJf+yiCWR+Up38jdEzQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794326808; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=0DDeYZpHzzROguF9lyPuaY1CHJCR9h3uzMreqdW2gJs=; b=o7SOtXIntS/EHsmn05zC4xS/k/roNCg/7G9ehZASrRsNTCD6BSdEtOBcZWt7gqVnhGhB APmHNLleQHqJ5MdwgTyIwbDofAhWD1XRjauE5XWyy2+82+eq3pR0SEDLiQWNMiNvszMoA aNzSu5KCUHOz001/w7HXp0mDlA/1iA37cWWoF2ZoMYdERsB3g2R2GI+3qEQVHC8IGk7zE pFcB4/0u03fQQfdf1FTvQx1vt7FKKbyyoh40iEClaFGBGKUoxcQifZ4rU2G1ZJpjpTK8Q MtTIfp8D16+dFljyQrX4tp1NgVdEN5vT954RxrSi51UA+4n9deW8ufAabMewMGq+RsA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fBNURoF3; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 697D6606A31C; Tue, 10 Nov 2026 16:06:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fBNURoF3 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF7F51F008A4; Tue, 10 Nov 2026 16:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794326807; bh=0DDeYZpHzzROguF9lyPuaY1CHJCR9h3uzMreqdW2gJs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=fBNURoF3SpIQ+1u/L/vJH9yTi7jjpF/LfGmCnCS4ZlB43sq325sk25Xln1uDyKGm0 lOuDjlBdR2vc4gxKnWLP4FZr7KWMvp1KCcuInFw+KgGwJTPcQ/DckxtStIy4hvaIn8 uBB9SiYySA5YEGXwT1YwT3B3Qjxr14x/B2roBES2YBfPYQ9WUVy7hY3fALkNo3vCA8 i/6Ng50rzinheI71+x8dM2Y6sTh91nyPuwmBqt+BeKDusgGngDpBsRb3nhevl2UuNC aQnayy0nanbgbQQEpcDLau3rWsVH3hGrNNDPZG90a4lNdQUeNnqxGw7RngHtXRSVEb OBzz5ffKARBBQ== Date: Tue, 10 Nov 2026 06:06:46 -1000 From: Tejun Heo To: Zhe Liu Cc: axboe@kernel.dk, josef@toxicpanda.com, yukuai@fygo.io, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH 0/3] blkcg: decouple cgroup v1 I/O accounting from throttling Message-ID: References: <20261110103201.762861-1-liuzhe1@kylinos.cn> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261110103201.762861-1-liuzhe1@kylinos.cn> On Tue, Nov 10, 2026 at 06:31:58PM +0800, Zhe Liu wrote: > Commit a3166c51702b ("blk-throttle: delay initialization until > configuration") deferred throttle policy activation until an I/O limit is > configured. However, cgroup v1 accounting still lives in the throttle > policy and is performed after the activation check in blk_should_throtl(). > Without an activated throttle policy, v1 statistics such as > blkio.throttle.io_service_bytes remain zero even while I/O is issued. > > This forces cgroup v1 users to configure the throttle policy just > to obtain I/O statistics, even when no throttling is needed. Maybe just add a module option or sth to blk-throtl to initialize eagerly? I don't think it makes sense to update cgroup1 significnatly at this point. Thanks. -- tejun