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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 69193C2D0F2 for ; Wed, 1 Apr 2020 08:47:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3660621835 for ; Wed, 1 Apr 2020 08:47:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3660621835 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B9CF06B00A8; Wed, 1 Apr 2020 04:47:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B4D386B00A9; Wed, 1 Apr 2020 04:47:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A63E86B00AA; Wed, 1 Apr 2020 04:47:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0094.hostedemail.com [216.40.44.94]) by kanga.kvack.org (Postfix) with ESMTP id 90C3E6B00A8 for ; Wed, 1 Apr 2020 04:47:11 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4D6E3180AE1C0 for ; Wed, 1 Apr 2020 08:47:11 +0000 (UTC) X-FDA: 76658656662.15.brick07_78eace726fd04 X-HE-Tag: brick07_78eace726fd04 X-Filterd-Recvd-Size: 3080 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Wed, 1 Apr 2020 08:47:10 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D5201ACE8; Wed, 1 Apr 2020 08:47:08 +0000 (UTC) Subject: Re: [PATCH 3/3] kernel/hung_task convert hung_task_panic boot parameter to sysctl To: Tetsuo Handa Cc: Luis Chamberlain , Kees Cook , Iurii Zaikin , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-mm@kvack.org, Ivan Teterevkov , Michal Hocko , David Rientjes , Matthew Wilcox , "Eric W . Biederman" , "Guilherme G . Piccoli" , Alexey Dobriyan , Thomas Gleixner , Greg Kroah-Hartman , Christian Brauner References: <20200330115535.3215-1-vbabka@suse.cz> <20200330115535.3215-4-vbabka@suse.cz> <2ee52caa-0257-19bd-28ef-60a2b4041a8d@I-love.SAKURA.ne.jp> From: Vlastimil Babka Message-ID: <9a11d5c9-b830-040e-219a-64cdb24a9236@suse.cz> Date: Wed, 1 Apr 2020 10:47:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <2ee52caa-0257-19bd-28ef-60a2b4041a8d@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 4/1/20 1:12 AM, Tetsuo Handa wrote: > On 2020/03/30 20:55, Vlastimil Babka wrote: >> @@ -63,16 +63,6 @@ static struct task_struct *watchdog_task; >> unsigned int __read_mostly sysctl_hung_task_panic = >> CONFIG_BOOTPARAM_HUNG_TASK_PANIC_VALUE; >> >> -static int __init hung_task_panic_setup(char *str) >> -{ >> - int rc = kstrtouint(str, 0, &sysctl_hung_task_panic); >> - >> - if (rc) >> - return rc; >> - return 1; >> -} >> -__setup("hung_task_panic=", hung_task_panic_setup); > > Can we defer removal of this handler for "one release cycle" (and instead emit a line > saying that "this parameter will be replaced by ..." during that cycle) ? I welcome The old parameter is not removed, it's just handled differently, see patch 2. Both old name and new sysctl.name will work. > PATCH 1/3, but kernel testing projects (e.g. syzbot) needs to update their settings > between PATCH 1/3 was merged into linux.git and PATCH 3/3 is merged into linux.git . > > https://lkml.kernel.org/r/CACT4Y+YE-j5ncjTGN6UhngfCNRgVo-QDZ3VCBGACdbs9-v+axQ@mail.gmail.com says > "Announcing unmerged changes is too early (as this patch showed). And once it's in linux-next it's already too late.." > >> - >> static int >> hung_task_panic(struct notifier_block *this, unsigned long event, void *ptr) >> { >> >