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 X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B6DFC433E0 for ; Thu, 28 May 2020 15:02:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E72D52084C for ; Thu, 28 May 2020 15:02:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=web.de header.i=@web.de header.b="IsgGFPf7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404148AbgE1PCz (ORCPT ); Thu, 28 May 2020 11:02:55 -0400 Received: from mout.web.de ([217.72.192.78]:51121 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403800AbgE1PCt (ORCPT ); Thu, 28 May 2020 11:02:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1590678139; bh=XAlZ9NlFpmpE4T1vzDKjCyi79kivASTGD6nypBrWwyU=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=IsgGFPf7bd45fb9vMm5tRv2jjsFQXKrY+PEODjX0mtbq1BOoGkk5/A1+y88O3fT57 sL7leqDtKPS1Dw0903JlCHlN/q2wBJIwhqYkKgDsRXR2S8UlSAC4wXh9slhFU8bmlO MDaaZlHsujpTds+Q/0rdY5LfAy7YAvf/qjrv0iik= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.3] ([2.244.30.242]) by smtp.web.de (mrweb102 [213.165.67.124]) with ESMTPSA (Nemesis) id 0LtWsC-1iv3eB29Js-010qQl; Thu, 28 May 2020 17:02:19 +0200 Subject: Re: [v5] workqueue: Remove unnecessary kfree() call in rcu_free_wq() To: Lai Jiangshan , Dan Carpenter , Tejun Heo Cc: Zhang Qiang , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org References: <20200527075715.36849-1-qiang.zhang@windriver.com> <284c7851-4e89-a00f-a2e6-aa8e2e1f3fce@web.de> <20200528095703.GH30374@kadam> From: Markus Elfring Autocrypt: addr=Markus.Elfring@web.de; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:m8Nb+gm7ddRTAwolHNsbKh/GSmMHQ6cirgzVxUHbZ7RxucNLHJF AlLRX4B39QB3xTGy59+x9SWxRFs9BOaiEGYP90drtRO2P/6nBnjvFGIcHyqdLNcpertRZ+P Il5ZnoAxVzfpGB/MSphAz9LNOjPwRlRRzPb17KZXqUqmpS5q3+0m3hUDtxUzN6vaTj7lpmM K/KGUCGNEShsOT6FDa0HQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:3smnmiaUYgQ=:/59f5bLFWdNcGEWBMo7Qy8 AWRhn+SbzJtGbWsM0wB3Wso73w/tJB5ltEkSxXTPYdQ2XHsUGccU06CQKTxcpf734gzZz8fDY 23P0Jj1zrbfln3x7vVF1mvB8AgJYTvBrNrLXqJr5LyUnZeu4/9y7PpufBHtaXWe/AutqVlfHv yaMX2YKUqlDbZb4/jmSiYIkyV97PEleVBdcz40zSvGxWJXj+Vg5VwxOLAHm9d9E9E9YleeLth bUA5f+I7QCiq7ZxhlFwnIPenONYCyngpOT6ykbYN93B0PbEIF2hBkVZNDoTsEUmINaqTE5tEj WoQneVncOpLUbnsAHP4BtIcKKE6hTn4ir7cwJdCZgmXlPJoGIT6rWgMxOHwm2Cg9PUm5Nw1o/ smuqy4Xat/kzeXTN0HPqy1663ibeHUpb8eLxHTOPy82nu4uHfBfXs+pGfcz3LSI9FS3ktT65s H4WZ9ieBHLGniv6CcxALYsQwh8XAHk055lZ/uFmqLqUo5zHSqcoSXdlTwy9eYn6htTsOGrW3/ yd0pG/7kke2Q4WMUG0UYFRRpZy8+dg7mkRkVt1sXtZLk/rT3/uytsunNZlV2hPelQJMv9Zt5M 8WinppMPg4/O4H5+qcVItctA+z08j60yBWBD2H+5R66e99LTg8mIDNwOVIlqv7n4jA9efFhaj jEkj417ZYFmx8RHupWlRebg2ebvPmbexJPmF2oVfwy9CCOQMveGS//tHn3FKFJ3QCwILL+VWi I49HRfvvxucUJKcB//tbaDm3LET0VT98f7Nabcb1oEHSU6obc7SE42EYtVFiRvovO8yZTgJdk qt3EwhDLygb2XXwL8tic9Cv0nNvE8rgn2oAXeOMgDCKwRWG5sWQ3OlmkcI4n5Hg8wHWDOsdy3 nz4hqBH98GyglTaQqXHVgp+LPO1ZaQ20wDTplK4ugQ2KUiGKoBgM97tDiFofxGQLitFSgs3TF +1Z2atwj1rQ6B9UWujZd1IsUYxR7hyo363e6PPreql5DHVK+0eepUb0JBahEHQOkar1JNVzwQ QruWo0szL6+dGo7pKF4lTUBVmGk4SwAs0ZP2IHMSy4FxLcAQ7nRInQl2RdwvGLUuio2FxUaDC gFfq6mQw7UrkydvM/rwu+2E5sbKUL97QkhAUrVy4d9nqhSCyVME3bwkvfRKU0yiF1IHK+KWf2 OtdJ9Buw1lSy46E3C/gX86c+fS/s19AgPN/bhnPgxn5TzmyIum5bpK4zCu5lbi64wYPYtb/Dn QZaDLViBE70As7bjY Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I'm also confused why they have been debating about the changelog > after the patch was queued. I suggest to take another look at the provided patch review comments. > My statement was about "the patch is a correct cleanup, > but the changelog is totally misleading". The commit message was accordingly adjusted, wasn't it? > destroy_workqueue(percpu_wq) -> rcu_free_wq() > or > destroy_workqueue(unbound_wq) -> put_pwq() -> > pwq_unbound_release_workfn() -> rcu_free_wq() > > So the patch is correct to me. Only can destroy_workqueue() > lead to rcu_free_wq(). > > Still, the kfree(NULL) is harmless. But it is cleaner > to have the patch. Thanks for such a feedback. > But the changelog is wrong, even after the lengthened debating, Do you expect any corresponding improvements? > and English is not my mother tongue, so I just looked on. How will the patch review evolve further despite of this information? Regards, Markus