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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 804DBC3F2D2 for ; Fri, 28 Feb 2020 20:54:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5525A2469F for ; Fri, 28 Feb 2020 20:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726773AbgB1Uym (ORCPT ); Fri, 28 Feb 2020 15:54:42 -0500 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:56494 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725805AbgB1Uym (ORCPT ); Fri, 28 Feb 2020 15:54:42 -0500 Received: from callcc.thunk.org (guestnat-104-133-8-109.corp.google.com [104.133.8.109] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 01SKrY6Q026237 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 28 Feb 2020 15:53:37 -0500 Received: by callcc.thunk.org (Postfix, from userid 15806) id 22DA1421A71; Fri, 28 Feb 2020 15:53:34 -0500 (EST) Date: Fri, 28 Feb 2020 15:53:34 -0500 From: "Theodore Y. Ts'o" To: Petr Mladek Cc: Greg Kroah-Hartman , Sergey Senozhatsky , Lech Perczak , Steven Rostedt , "linux-kernel@vger.kernel.org" , Arnd Bergmann , Krzysztof =?utf-8?Q?Drobi=C5=84ski?= , Pawel Lenkow , John Ogness , Tejun Heo , Peter Zijlstra Subject: Re: Regression in v4.19.106 breaking waking up of readers of /proc/kmsg and /dev/kmsg Message-ID: <20200228205334.GF101220@mit.edu> References: <20200227123633.GB962932@kroah.com> <42d3ce5c-5ffe-8e17-32a3-5127a6c7c7d8@camlintechnologies.com> <20200228031306.GO122464@google.com> <20200228100416.6bwathdtopwat5wy@pathway.suse.cz> <20200228105836.GA2913504@kroah.com> <20200228113214.kew4xi5tkbo7bpou@pathway.suse.cz> <20200228130217.rj6qge2en26bdp7b@pathway.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200228130217.rj6qge2en26bdp7b@pathway.suse.cz> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 28, 2020 at 02:02:17PM +0100, Petr Mladek wrote: > > So, I would still prefer to _revert_ the commit 15341b1dd409749f > ("char/random: silence a lockdep splat with printk()"). It calmed > down lockdep report. The real life danger is dubious. The warning > is printed early when the system is running on single CPU where > it could not race. I'm wondering now if we should revert this commit before 5.6 comes out (it landed in 5.6-rc1). "Is much less likely to happen given the other random initialization patches" is not the same as "guaranteed not to happen". What do folks think? - Ted