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=-2.3 required=3.0 tests=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 E8FA1C33CB1 for ; Thu, 16 Jan 2020 14:29:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B5B8D21582 for ; Thu, 16 Jan 2020 14:29:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B5B8D21582 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3A0FE8E0072; Thu, 16 Jan 2020 09:29:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 351808E003F; Thu, 16 Jan 2020 09:29:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 267368E0072; Thu, 16 Jan 2020 09:29:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0174.hostedemail.com [216.40.44.174]) by kanga.kvack.org (Postfix) with ESMTP id 100F88E003F for ; Thu, 16 Jan 2020 09:29:59 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id D60742C12 for ; Thu, 16 Jan 2020 14:29:58 +0000 (UTC) X-FDA: 76383731676.24.spade11_914d5e9e4150a X-HE-Tag: spade11_914d5e9e4150a X-Filterd-Recvd-Size: 2415 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Thu, 16 Jan 2020 14:29:58 +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 8DE42B49E; Thu, 16 Jan 2020 14:29:56 +0000 (UTC) Date: Thu, 16 Jan 2020 15:29:54 +0100 From: Petr Mladek To: Qian Cai Cc: Michal Hocko , David Hildenbrand , Andrew Morton , sergey.senozhatsky.work@gmail.com, rostedt@goodmis.org, peterz@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -next] mm/hotplug: silence a lockdep splat with printk() Message-ID: <20200116142954.l6gttssy65tuwygd@pathway.suse.cz> References:<20200115095253.36e5iqn77n4exj3s@pathway.suse.cz> <20200115170235.ph7lrojaktmfikm2@pathway.suse.cz> <7CD27FC6-CFFF-4519-A57D-85179E9815FE@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To:<7CD27FC6-CFFF-4519-A57D-85179E9815FE@lca.pw> User-Agent: NeoMutt/20170912 (1.9.0) Content-Transfer-Encoding: quoted-printable 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 Wed 2020-01-15 12:16:17, Qian Cai wrote: >=20 >=20 > > On Jan 15, 2020, at 12:02 PM, Petr Mladek wrote: > >=20 > > On Wed 2020-01-15 06:49:03, Qian Cai wrote: > >>=20 > >>=20 > >>> On Jan 15, 2020, at 4:52 AM, Petr Mladek wrote: > >>>=20 > >>> I could understand that Michal is against hack in -mm code that > >>> would just hide a false positive warning. > >>=20 > >> Well, I don=E2=80=99t have any confidence to say everything this pat= ch is > >> trying to fix is false positives. > >=20 > > You look at this from a wrong angle. AFAIK, all lockdep reports paste= d > > in the below mentioned thread were false positives. Now, this patch > > complicates an already complicated -mm code to hide the warning > > and fix theoretical problems. >=20 > What makes you say all of those are false positives? I have to admit that the 3 provided lockdep reports really looked suspicious. I must have somehow missed/forgot about them. If the last proposed change removes them and is acceptable for -mm people then it looks like a reasonable solution. Best Regards, Petr