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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 42E3AC433DF for ; Thu, 11 Jun 2020 02:21:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ACB02072F for ; Thu, 11 Jun 2020 02:21:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726462AbgFKCVd (ORCPT ); Wed, 10 Jun 2020 22:21:33 -0400 Received: from mga11.intel.com ([192.55.52.93]:54271 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726163AbgFKCVd (ORCPT ); Wed, 10 Jun 2020 22:21:33 -0400 IronPort-SDR: WjpSEb5mJSCFMt7WcSmNAmGZ7GKpI9RKKNCXvImrgwc9k5ZDnL3Eb7lCM49GZxFOAhpRdZJi2c O5DZm94IxqDg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2020 19:21:33 -0700 IronPort-SDR: crHdxxHrEsrSH17RRKCC8W6WOJ1FhQ0Lzw7W/xbrTzgcSHk2h/TNE66eFmKFisD6/Q9o1nubH8 hiiYrLp2H2hA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,498,1583222400"; d="scan'208";a="473644260" Received: from sshen-mobl1.ccr.corp.intel.com (HELO [10.255.28.22]) ([10.255.28.22]) by fmsmga005.fm.intel.com with ESMTP; 10 Jun 2020 19:21:12 -0700 Subject: Re: [kmemleak] b751c52bb5: BUG:kernel_hang_in_boot_stage To: Catalin Marinas , kernel test robot Cc: Nicolas Boichat , Linus Torvalds , Dmitry Vyukov , Masahiro Yamada , Kees Cook , Petr Mladek , Thomas Gleixner , Tetsuo Handa , Joe Lawrence , Uladzislau Rezki , Andy Shevchenko , Stephen Rothwell , Andrey Ryabinin , Andrew Morton , LKML , lkp@lists.01.org References: <20200610075156.GE12456@shao2-debian> <20200610105640.GB26099@gaia> From: Li Zhijian Message-ID: <8795ed06-d67f-7bfe-506b-4f1d79e0170e@intel.com> Date: Thu, 11 Jun 2020 10:20:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20200610105640.GB26099@gaia> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/10/20 6:56 PM, Catalin Marinas wrote: > On Wed, Jun 10, 2020 at 03:51:56PM +0800, kernel test robot wrote: >> FYI, we noticed the following commit (built with gcc-7): >> >> commit: b751c52bb587ae66f773b15204ef7a147467f4c7 ("kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16K") >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master >> >> in testcase: boot >> >> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G > [...] >> BUG: kernel hang in boot stage >> >> To reproduce: >> >> # build kernel >> cd linux >> cp config-5.3.0-11789-gb751c52bb587a .config >> make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 olddefconfig prepare modules_prepare bzImage > I've never tried kmemleak on i386. > > Anyway, I'm not sure what caused the hang (or whether it's a hang at > all) but I suspect prior to the above commit, kmemleak probably just > disabled itself (early log buffer exceeded). > So the bug may have been > there already, I think so > only that kmemleak started working and tripped over it > when the log buffer increased. > > Is there a chance that the kernel got much slower with kmemleak enabled > and the test scripts timed out? > Does this problem still exist with the latest mainline? Yes, that's true. Thanks Zhijian (0Day CI team) > > Thanks. >