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 F079AC33CB6 for ; Thu, 16 Jan 2020 14:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDDD821D56 for ; Thu, 16 Jan 2020 14:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726778AbgAPO36 (ORCPT ); Thu, 16 Jan 2020 09:29:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:40210 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726088AbgAPO36 (ORCPT ); Thu, 16 Jan 2020 09:29:58 -0500 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 Content-Transfer-Encoding: 8bit In-Reply-To: <7CD27FC6-CFFF-4519-A57D-85179E9815FE@lca.pw> User-Agent: NeoMutt/20170912 (1.9.0) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 2020-01-15 12:16:17, Qian Cai wrote: > > > > On Jan 15, 2020, at 12:02 PM, Petr Mladek wrote: > > > > On Wed 2020-01-15 06:49:03, Qian Cai wrote: > >> > >> > >>> On Jan 15, 2020, at 4:52 AM, Petr Mladek wrote: > >>> > >>> I could understand that Michal is against hack in -mm code that > >>> would just hide a false positive warning. > >> > >> Well, I don’t have any confidence to say everything this patch is > >> trying to fix is false positives. > > > > You look at this from a wrong angle. AFAIK, all lockdep reports pasted > > 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. > > 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