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[23.128.96.18]) by mx.google.com with ESMTP id cx22si3850301edb.429.2020.05.28.08.06.54; Thu, 28 May 2020 08:07:20 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@web.de header.s=dbaedf251592 header.b=IsgGFPf7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403981AbgE1PCv (ORCPT + 99 others); Thu, 28 May 2020 11:02:51 -0400 Received: from mout.web.de ([212.227.17.12]:41941 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403912AbgE1PCs (ORCPT ); Thu, 28 May 2020 11:02:48 -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 (mrweb106 [213.165.67.124]) with ESMTPSA (Nemesis) id 1MG9DC-1joFex1Uia-00Germ; 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; prefer-encrypt=mutual; keydata= mQINBFg2+xABEADBJW2hoUoFXVFWTeKbqqif8VjszdMkriilx90WB5c0ddWQX14h6w5bT/A8 +v43YoGpDNyhgA0w9CEhuwfZrE91GocMtjLO67TAc2i2nxMc/FJRDI0OemO4VJ9RwID6ltwt mpVJgXGKkNJ1ey+QOXouzlErVvE2fRh+KXXN1Q7fSmTJlAW9XJYHS3BDHb0uRpymRSX3O+E2 lA87C7R8qAigPDZi6Z7UmwIA83ZMKXQ5stA0lhPyYgQcM7fh7V4ZYhnR0I5/qkUoxKpqaYLp YHBczVP+Zx/zHOM0KQphOMbU7X3c1pmMruoe6ti9uZzqZSLsF+NKXFEPBS665tQr66HJvZvY GMDlntZFAZ6xQvCC1r3MGoxEC1tuEa24vPCC9RZ9wk2sY5Csbva0WwYv3WKRZZBv8eIhGMxs rcpeGShRFyZ/0BYO53wZAPV1pEhGLLxd8eLN/nEWjJE0ejakPC1H/mt5F+yQBJAzz9JzbToU 5jKLu0SugNI18MspJut8AiA1M44CIWrNHXvWsQ+nnBKHDHHYZu7MoXlOmB32ndsfPthR3GSv jN7YD4Ad724H8fhRijmC1+RpuSce7w2JLj5cYj4MlccmNb8YUxsE8brY2WkXQYS8Ivse39MX BE66MQN0r5DQ6oqgoJ4gHIVBUv/ZwgcmUNS5gQkNCFA0dWXznQARAQABtCZNYXJrdXMgRWxm cmluZyA8TWFya3VzLkVsZnJpbmdAd2ViLmRlPokCVAQTAQgAPhYhBHDP0hzibeXjwQ/ITuU9 Figxg9azBQJYNvsQAhsjBQkJZgGABQsJCAcCBhUICQoLAgQWAgMBAh4BAheAAAoJEOU9Figx g9azcyMP/iVihZkZ4VyH3/wlV3nRiXvSreqg+pGPI3c8J6DjP9zvz7QHN35zWM++1yNek7Ar OVXwuKBo18ASlYzZPTFJZwQQdkZSV+atwIzG3US50ZZ4p7VyUuDuQQVVqFlaf6qZOkwHSnk+ CeGxlDz1POSHY17VbJG2CzPuqMfgBtqIU1dODFLpFq4oIAwEOG6fxRa59qbsTLXxyw+PzRaR LIjVOit28raM83Efk07JKow8URb4u1n7k9RGAcnsM5/WMLRbDYjWTx0lJ2WO9zYwPgRykhn2 sOyJVXk9xVESGTwEPbTtfHM+4x0n0gC6GzfTMvwvZ9G6xoM0S4/+lgbaaa9t5tT/PrsvJiob kfqDrPbmSwr2G5mHnSM9M7B+w8odjmQFOwAjfcxoVIHxC4Cl/GAAKsX3KNKTspCHR0Yag78w i8duH/eEd4tB8twcqCi3aCgWoIrhjNS0myusmuA89kAWFFW5z26qNCOefovCx8drdMXQfMYv g5lRk821ZCNBosfRUvcMXoY6lTwHLIDrEfkJQtjxfdTlWQdwr0mM5ye7vd83AManSQwutgpI q+wE8CNY2VN9xAlE7OhcmWXlnAw3MJLW863SXdGlnkA3N+U4BoKQSIToGuXARQ14IMNvfeKX NphLPpUUnUNdfxAHu/S3tPTc/E/oePbHo794dnEm57LuuQINBFg2+xABEADZg/T+4o5qj4cw nd0G5pFy7ACxk28mSrLuva9tyzqPgRZ2bdPiwNXJUvBg1es2u81urekeUvGvnERB/TKekp25 4wU3I2lEhIXj5NVdLc6eU5czZQs4YEZbu1U5iqhhZmKhlLrhLlZv2whLOXRlLwi4jAzXIZAu 76mT813jbczl2dwxFxcT8XRzk9+dwzNTdOg75683uinMgskiiul+dzd6sumdOhRZR7YBT+xC wzfykOgBKnzfFscMwKR0iuHNB+VdEnZw80XGZi4N1ku81DHxmo2HG3icg7CwO1ih2jx8ik0r riIyMhJrTXgR1hF6kQnX7p2mXe6K0s8tQFK0ZZmYpZuGYYsV05OvU8yqrRVL/GYvy4Xgplm3 DuMuC7/A9/BfmxZVEPAS1gW6QQ8vSO4zf60zREKoSNYeiv+tURM2KOEj8tCMZN3k3sNASfoG fMvTvOjT0yzMbJsI1jwLwy5uA2JVdSLoWzBD8awZ2X/eCU9YDZeGuWmxzIHvkuMj8FfX8cK/ 2m437UA877eqmcgiEy/3B7XeHUipOL83gjfq4ETzVmxVswkVvZvR6j2blQVr+MhCZPq83Ota xNB7QptPxJuNRZ49gtT6uQkyGI+2daXqkj/Mot5tKxNKtM1Vbr/3b+AEMA7qLz7QjhgGJcie qp4b0gELjY1Oe9dBAXMiDwARAQABiQI8BBgBCAAmFiEEcM/SHOJt5ePBD8hO5T0WKDGD1rMF Alg2+xACGwwFCQlmAYAACgkQ5T0WKDGD1rOYSw/+P6fYSZjTJDAl9XNfXRjRRyJSfaw6N1pA Ahuu0MIa3djFRuFCrAHUaaFZf5V2iW5xhGnrhDwE1Ksf7tlstSne/G0a+Ef7vhUyeTn6U/0m +/BrsCsBUXhqeNuraGUtaleatQijXfuemUwgB+mE3B0SobE601XLo6MYIhPh8MG32MKO5kOY hB5jzyor7WoN3ETVNQoGgMzPVWIRElwpcXr+yGoTLAOpG7nkAUBBj9n9TPpSdt/npfok9ZfL /Q+ranrxb2Cy4tvOPxeVfR58XveX85ICrW9VHPVq9sJf/a24bMm6+qEg1V/G7u/AM3fM8U2m tdrTqOrfxklZ7beppGKzC1/WLrcr072vrdiN0icyOHQlfWmaPv0pUnW3AwtiMYngT96BevfA qlwaymjPTvH+cTXScnbydfOQW8220JQwykUe+sHRZfAF5TS2YCkQvsyf7vIpSqo/ttDk4+xc Z/wsLiWTgKlih2QYULvW61XU+mWsK8+ZlYUrRMpkauN4CJ5yTpvp+Orcz5KixHQmc5tbkLWf x0n1QFc1xxJhbzN+r9djSGGN/5IBDfUqSANC8cWzHpWaHmSuU3JSAMB/N+yQjIad2ztTckZY pwT6oxng29LzZspTYUEzMz3wK2jQHw+U66qBFk8whA7B2uAU1QdGyPgahLYSOa4XAEGb6wbI FEE= Message-ID: <75afce2b-cdf0-b917-cab5-f36d105abcfc@web.de> Date: Thu, 28 May 2020 17:02:18 +0200 User-Agent: Mozilla/5.0 (X11; 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:SyQea2mcR7kZajl+TazE9ttwxonaCGfXKQ2UnI3DIy2jOqVknLK NSVku7ElU39PDHnalEfvGxWNU6tAlz1UdBstByK+owtpPhevM2ebWZT42GToGdUSLefjgEk qAobBy4LQUAzBOfiDdTbhgPFWcyk659vL/mLrG157mff1nZUu3QvN3fFskluVpM/5J8hjvl eV1f3zHQCUWn5cxQH/yuA== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:AczgUwj0+1g=:fqQvrpBy7yOvwjP+2RzH4P GXMkj5L+E3sKg/4fyrvsjXFe5zyhN83XHf/jXbe+JTakbzzOX//AFUtZSatUF9ajfu/8F+DwW b7p48G1ZSEkqPqAkoGmbJFeorz0cghvcUwTMeTIZREexTQo6lEpBIm/76os4dbwdqCEh60Oqg uw3Bp/GH7JnwkTVNeBFV1V85Q1VIq1n3XvS+vuVJGnRkO+TlY72XvniyH7md++5Z9gOwlR85p LdLRektbUJwmAYsRVtC5MqgICkHH56lNVTWMhbt3NziHv8L8ZliMposRyi15FWxAruEq7O7kQ nsiH24y+a80+ZzfEeqchBqGaSY+vFOnT0YYtHKkfC9USCMpZduEtPRlIjDbBcjcKdzpsZsoyI RYRyie42/X98bz8xfjhM478JDes7Tbpuu0Ik9zA8JymjN2IUhKWllODqojK6Q5ClvMNgEzaK3 HX8o9UdGst60qGVgXEfCC3qKsmnDJmWN1iWx5SCJ0w18F1ClyNSHVdCDv1ej6SLJ30wniLmS2 zs73ttW7Wm1hZoJOE9D0K3bfEAOuZOUkBlM7qhRoHMbbV+wK6/xeEw1Xw3wpgaMqC4AzTiCFo mcXaECKEaqqXCni37sJ/Wi/Lxo+LZvmxv35OW0rB1bfoW9sDii/71oG5O/aEnuufGpp3O1lCV b+B9397ZLcm5u3DzvwEVOvLG2LIaeR3jeJ6x11iRTpVEYZuHmG2o7D5dPUO8Is+I5+m/SGp9G tPmU70gHqrPssc8xcwlU+HZqEn4mP9VySol03OUvLl7pS5Apbo7gB8u7CzXC2pntNOrBFVcy4 gDostiZUrRpPsnX7XNFn7ISZGlVERHPCVppGi4cSw3Dwi0MhEFxffSep4XR6nfJMG8PWzcxIB FgRztVuevYe0164+mlwfMz9V94AX0bAwzAI3PkN7LYiA758lZJUyeLgu7s2zxsWmEOlRlg5N7 ffpNziy+0IKYw1tf6Q42sF3zDqnjvH35YAMa4GlLa+j+EaFkxhIWFlBpcB0d+EETffEyfDhs/ SCzbZYZMv6aUs+u/gqE2H1ea+EetoS/etoyK6HTejr9VAvMUd17KdU53DAVt4GCR75kwaRkbE ofjxia0hff2wqvWEmVAqxZg0wHaEvyADgR/x4j+Jj2GHXYwhN639AJ0UoTaLsU2QL9caDXL6q Ki4pqpD1oFeBiTIi2B8yK8O9CY9jR19Tle9Ra0/qG7PIf+dlb2bHiWiQ4niTMb05sxrZTO9tJ 8S5EKNmYYE+r9Zv1w 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