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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS 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 CC269C43387 for ; Mon, 17 Dec 2018 17:27:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3A9C20675 for ; Mon, 17 Dec 2018 17:27:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732878AbeLQR1m (ORCPT ); Mon, 17 Dec 2018 12:27:42 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:37973 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726436AbeLQR1m (ORCPT ); Mon, 17 Dec 2018 12:27:42 -0500 Received: by mail-pf1-f196.google.com with SMTP id q1so6699261pfi.5 for ; Mon, 17 Dec 2018 09:27:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=823vNceqOZW1qhO1NubhUnPzY9PiHcOak7MQZp1+gtg=; b=MH+DSScZNizEIxEDyB+05OpuP6a0SfXVEo8V7ocxYSr5m0gVs9sCUdd+rPbd8MaRLX lGvq+RsZwdmpOQKpZ01Afbe1UGIUbaVaXIEBFzVTXVbGPkyMpFnkYbEfamWzy+mNXCw+ E12vB2B62rbsxHm+GrIA40UR2NR8+KjwLuIewd8Au2koo6HsQDrRRag1qIPkPqN4hJm/ FbZjK581y/Ff7kNbMuGFhtu2dxR6vFcZY/7rosWeIIwIVlO5dbzlm189sduyXLfx0VlB XKwFweEIw7ofmGmeS4I2PyNT4OZ9Rc4uWG/RUWvfivhg4PQzE7M9R44/XToZw/5qhmpD wRtA== X-Gm-Message-State: AA+aEWZVA5wm3FhBj45+2DgGw+QtzyjUlVasb1GP5imIshhMtbWxyF31 /xafmPINUY1jThIVEl4xe9Y= X-Google-Smtp-Source: AFSGD/UMeh/+NcwiHAvk6yZ4DUDFFJJYKQO95uvQw+ViJM9zubLef6Zw2WzZrpyWSDm3Bh34eZlvfQ== X-Received: by 2002:a62:3811:: with SMTP id f17mr13863166pfa.206.1545067660861; Mon, 17 Dec 2018 09:27:40 -0800 (PST) Received: from ?IPv6:2620:15c:2cd:203:5cdc:422c:7b28:ebb5? ([2620:15c:2cd:203:5cdc:422c:7b28:ebb5]) by smtp.gmail.com with ESMTPSA id a18sm15778264pgj.30.2018.12.17.09.27.38 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 17 Dec 2018 09:27:39 -0800 (PST) Message-ID: <1545067657.185366.433.camel@acm.org> Subject: Re: [LKP] [locking/lockdep] 15693f040b: WARNING:at_kernel/locking/lockdep.c:#lockdep_free_key_range From: Bart Van Assche To: kernel test robot Cc: Peter Zijlstra , Waiman Long , Johannes Berg , LKML , Bart Van Assche , lkp@01.org Date: Mon, 17 Dec 2018 09:27:37 -0800 In-Reply-To: <20181217084128.GE23332@shao2-debian> References: <20181217084128.GE23332@shao2-debian> Content-Type: text/plain; charset="UTF-7" X-Mailer: Evolution 3.26.2-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-12-17 at 16:41 +-0800, kernel test robot wrote: +AD4 FYI, we noticed the following commit (built with gcc-4.9): +AD4 +AD4 commit: 15693f040b149ffff598cc048c2697b258d3901c (+ACI-locking/lockdep: Free lock classes that are no longer in use+ACI) +AD4 https://github.com/bvanassche/linux for-next +AD4 +AD4 in testcase: locktorture +AD4 with following parameters: +AD4 +AD4 runtime: 300s +AD4 test: cpuhotplug +AD4 +AD4 test-description: This torture test consists of creating a number of kernel threads which acquire the lock and hold it for specific amount of time, thus simulating different critical region +AD4 behaviors. +AD4 test-url: https://www.kernel.org/doc/Documentation/locking/locktorture.txt +AD4 +AD4 +AD4 on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 512M +AD4 +AD4 caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +AD4 +AD4 +AD4 +--------------------------------------------------------------+-------------+-------------+- +AD4 +AD4 +AHw b7001c6cce +AHw 15693f040b +AHw +AD4 +AD4 +--------------------------------------------------------------+-------------+-------------+- +AD4 +AD4 boot+AF8-successes +AHw 0 +AHw 0 +AHw +AD4 +AD4 boot+AF8-failures +AHw 394 +AHw 396 +AHw +AD4 +AD4 WARNING:at+AF8-lib/debugobjects.c:+ACMAXwBf-debug+AF8-object+AF8-init +AHw 394 +AHw 396 +AHw +AD4 +AD4 EIP:+AF8AXw-debug+AF8-object+AF8-init +AHw 394 +AHw 396 +AHw +AD4 +AD4 WARNING:possible+AF8-circular+AF8-locking+AF8-dependency+AF8-detected +AHw 370 +AHw 375 +AHw +AD4 +AD4 WARNING:at+AF8-kernel/locking/lockdep.c:+ACM-lock+AF8-downgrade +AHw 145 +AHw 159 +AHw +AD4 +AD4 EIP:lock+AF8-downgrade +AHw 145 +AHw 159 +AHw +AD4 +AD4 BUG:soft+AF8-lockup-CPU+ACMAIw-stuck+AF8-for+ACM-s +AHw 24 +AHw 21 +AHw +AD4 +AD4 EIP:thread+AF8-lookup+AF8-test +AHw 12 +AHw 9 +AHw +AD4 +AD4 Kernel+AF8-panic-not+AF8-syncing:softlockup:hung+AF8-tasks +AHw 24 +AHw 21 +AHw +AD4 +AD4 EIP:memcmp +AHw 3 +AHw 3 +AHw +AD4 +AD4 EIP:threadfunc +AHw 4 +AHw 2 +AHw +AD4 +AD4 EIP:lock+AF8-acquire +AHw 3 +AHw 1 +AHw +AD4 +AD4 EIP:lock+AF8-is+AF8-held+AF8-type +AHw 2 +AHw 2 +AHw +AD4 +AD4 WARNING:at+AF8-net/sched/sch+AF8-generic.c:+ACM-dev+AF8-watchdog +AHw 1 +AHw +AHw +AD4 +AD4 EIP:dev+AF8-watchdog +AHw 1 +AHw +AHw +AD4 +AD4 WARNING:at+AF8-kernel/locking/lockdep.c:+ACM-lockdep+AF8-free+AF8-key+AF8-range +AHw 0 +AHw 22 +AHw +AD4 +AD4 EIP:lockdep+AF8-free+AF8-key+AF8-range +AHw 0 +AHw 22 +AHw +AD4 +AD4 EIP:lock+AF8-release +AHw 0 +AHw 2 +AHw +AD4 +AD4 EIP:rht+AF8-deferred+AF8-worker +AHw 0 +AHw 2 +AHw +AD4 +AD4 +--------------------------------------------------------------+-------------+-------------+- The WARNING:at+AF8-kernel/locking/lockdep.c:+ACM-lockdep+AF8-free+AF8-key+AF8-range warnings were caused by the following code: pf +AD0 get+AF8-pending+AF8-free+AF8-lock(+ACY-flags)+ADs if (WARN+AF8-ON+AF8-ONCE(+ACE-pf)) return+ADs Before this report was produced I had already pushed out a new version of my lockdep patch series to the for-next branch of my github repository in which that code had been modified into the following: pf +AD0 get+AF8-pending+AF8-free+AF8-lock(+ACY-flags)+ADs if (+ACE-pf) return+ADs Since the above report refers to a WARN+AF8-ON+AF8-ONCE() statement that has been removed, I think that this report can be ignored. Bart.