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 88CE8C54EF0 for ; Thu, 5 Jan 2023 13:56:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234163AbjAEN4F (ORCPT ); Thu, 5 Jan 2023 08:56:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234161AbjAENzN (ORCPT ); Thu, 5 Jan 2023 08:55:13 -0500 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E1244A960; Thu, 5 Jan 2023 05:52:37 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4NnnwF1r4Zz4f3wRT; Thu, 5 Jan 2023 21:52:29 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP4 (Coremail) with SMTP id gCh0CgD3X7Me1rZjMeqZBA--.54696S3; Thu, 05 Jan 2023 21:52:31 +0800 (CST) Subject: Re: [PATCH] blk-cgroup: fix missing pd_online_fn() while activating policy To: =?UTF-8?Q?Michal_Koutn=c3=bd?= , Yu Kuai Cc: tj@kernel.org, josef@toxicpanda.com, axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, "yukuai (C)" References: <20230103112833.2013432-1-yukuai1@huaweicloud.com> <20230104151241.GA13268@blackbody.suse.cz> <4b559d1d-31e4-6049-4548-451bf7afb4f4@huaweicloud.com> <20230105104241.GA16920@blackbody.suse.cz> From: Yu Kuai Message-ID: <6f54c858-be91-0fd3-d377-1aabb8a70c6f@huaweicloud.com> Date: Thu, 5 Jan 2023 21:52:29 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20230105104241.GA16920@blackbody.suse.cz> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID: gCh0CgD3X7Me1rZjMeqZBA--.54696S3 X-Coremail-Antispam: 1UD129KBjvdXoW7Jr18WF4UJF1rGFW3XryxXwb_yoW3Xrb_uF 1UGry2kw45W3Z5Za17JrWrXFykC348JFyUZF93C3y5Zr1UZrZ7GFn8JFyfGw1UCwnaqr9F krsxJF40yrWSvjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb3kFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_ Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr 1lF7xvr2IY64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY 04v7Mxk0xIA0c2IEe2xFo4CEbIxvr21l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7 v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF 1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIx AIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0D MIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIda VFxhVjvjDU0xZFpf9x0JUdHUDUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, 在 2023/01/05 18:45, Michal Koutný 写道: > On Thu, Jan 05, 2023 at 09:43:02AM +0800, Yu Kuai wrote: >> This is based only on code review, currently the only negative effects >> is that root blkg from blk-throtl won't call pd_online_fn(). > > Good, that's a NOP and there are no other uses of pd_online_fn. > > I wonder are the separate pd_init_fn and pd_online_fn callbacks > necessary today? I think online can combine to init, consider that only blk-throttle implement pd_online_fn(), but I'm not sure... It seems to me the policies(bfq, iocost...) seem don't honor how pd apis works: alloc->init->online->offline->free, bfq combines online to init, iocost combines offline to free, ... Thanks, Kuai