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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 9989DC43381 for ; Tue, 26 Mar 2019 17:44:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 733D92070D for ; Tue, 26 Mar 2019 17:44:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732027AbfCZRoT (ORCPT ); Tue, 26 Mar 2019 13:44:19 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:42883 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726258AbfCZRoS (ORCPT ); Tue, 26 Mar 2019 13:44:18 -0400 Received: by mail-pl1-f193.google.com with SMTP id cv12so1980124plb.9 for ; Tue, 26 Mar 2019 10:44:18 -0700 (PDT) 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:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=xfE1mWZMTe2MUt3HB3oB5dCMGPVrq+8RT1AI4bTQq1I=; b=S3K4jdwTDJzeyzVgot0AoWXnLOJG3VrE+Rdlt18DixI87Cv6AswskOqAJ1PkuwT8cW kffC1ieqKuDe8DGF4CTtcYHKzV48d48XRxl2wg3H2sHYWalYqnP+BcCX6WOnfserXGAH sgCh2ZSP32r5w2OXBwYDr6IGC+gGlbc0v6/Ot726VSPHBafn7PXZID3cJGR24XeJq26w 2uUSFOLQOZv7T31sNlhUzwIqw2GUOl/OHpK6GkFopOixxVYru9g79jQ00wAa/jxQtQr3 +C+oy4cDLlVz2HHjCBhYeO093exAFSEv2w5oto8shw9jh5b1inQrap72GG86g43DLixb qczg== X-Gm-Message-State: APjAAAXdb17a/PntE1Sf0WhqD+40lENn0KdeiYJIc+P7I/tP7d5l46A6 Jb5fZrqDNipQvzbQDHNsP3o= X-Google-Smtp-Source: APXvYqxVk7UONmgup1r7TdgfAQY3R6JUUg0cDW+m6TWZ04KcPSdhDkkDEv64P2m5u/W+tC0y0jZuXA== X-Received: by 2002:a17:902:9043:: with SMTP id w3mr32126550plz.101.1553622258052; Tue, 26 Mar 2019 10:44:18 -0700 (PDT) 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 z189sm27904596pfb.146.2019.03.26.10.44.16 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 26 Mar 2019 10:44:16 -0700 (PDT) Message-ID: <1553622255.118779.69.camel@acm.org> Subject: Re: "cat /proc/lockdep" after "rmmod " when !debug_locks will crash the system From: Bart Van Assche To: shenghui , peterz@infradead.org, mingo@redhat.com, will.deacon@arm.com, linux-kernel@vger.kernel.org Date: Tue, 26 Mar 2019 10:44:15 -0700 In-Reply-To: <5c9973cc.1c69fb81.371e8.7b9fSMTPIN_ADDED_BROKEN@mx.google.com> References: <5c98a345.1c69fb81.21300.0be5SMTPIN_ADDED_BROKEN@mx.google.com> <1553527621.118779.2.camel@acm.org> <5c9973cc.1c69fb81.371e8.7b9fSMTPIN_ADDED_BROKEN@mx.google.com> 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 Tue, 2019-03-26 at 08:35 +-0800, shenghui wrote: +AD4 My test steps: +AD4 -------------- +AD4 1) bootup the system, and check the calltrace in dmesg. Just warning and ignore it. +AD4 2) cat /proc/lockdep +ACM everything is well +AD4 3) rmmod some module which provides lock+AF8-class in lockdep +AD4 In my system, module bcache is used: ('grep bcache /proc/lockdep' prints something) +AD4 +ACo stop bcache set +AD4 +ACo rmmod bcache +AD4 I have tried other module, e.g: rmmod iwldvm +AD4 4) cat /proc/lockdep +ACM system crash Hi shenghui, Thank you for having shared your test steps. I ran a slightly different test myself: while true+ADs do cat /proc/lockdep +AD4-/dev/null+ADs done +ACY (cd blktests +ACYAJg while ./check -q+ADs do :+ADs done) This test reads /proc/lockdep in a loop while running a test that stresses lockdep and also that loads and unloads kernel modules. Since this test passed on my setup I suggest that you have a close look at your setup. The vboxdrv kernel driver or an out-of-tree patch may be what is making your system unstable. Bart.