Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753199AbdLUPVF (ORCPT ); Thu, 21 Dec 2017 10:21:05 -0500 Received: from wolff.to ([98.103.208.27]:41182 "HELO wolff.to" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751855AbdLUPVD (ORCPT ); Thu, 21 Dec 2017 10:21:03 -0500 Date: Thu, 21 Dec 2017 09:18:43 -0600 From: Bruno Wolff III To: weiping zhang Cc: Laura Abbott , Jan Kara , Jens Axboe , linux-mm@kvack.org, Linux Kernel Mailing List , regressions@leemhuis.info, weiping zhang , linux-block@vger.kernel.org Subject: Re: Regression with a0747a859ef6 ("bdi: add error handle for bdi_debug_register") Message-ID: <20171221151843.GA453@wolff.to> References: <20171221130057.GA26743@wolff.to> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1494 Lines: 34 On Thu, Dec 21, 2017 at 22:01:33 +0800, weiping zhang wrote: >Hi, >how do you do bisect ?build all kernel commit one by one ? >as you did before: >https://bugzilla.redhat.com/show_bug.cgi?id=1520982 I just did the one bisect using Linus' tree. After each build, I would do a test boot and see if the boot was normal or if I got errors and an eventual hang before boot. Since then I have used git revert to revert just the problem commit from later kernels (such as v4.15-rc4) and when I do the system boots normally. And when I don't do the revert or just use stock Fedora kernels the problem occurs every time. I also did a couple of tests with Josh Boyer's Fedora kernel tree that has Fedora patches on top of the development kernel. >what kernel source code do you use that occur warning at device_add_disk? >from fedora or any official release ? if so ,could you provide web link? That was from an offical Fedora kernel. I believe I got it from the nodebug repo, but that kernel should be the same as the one that was normally used for rawhide. It is at https://koji.fedoraproject.org/koji/buildinfo?buildID=1007500 but I don't know how much longer the binaries will stay available in koji. >if you use same kernel source code and same .config, why your own build >Cann't trigger that warning ? I don't know. The install script may build the initramfs differently. As far as I can tell, if the WARN_ON was triggered, I should have gotten output.