Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755863Ab0AVDYp (ORCPT ); Thu, 21 Jan 2010 22:24:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754820Ab0AVDYo (ORCPT ); Thu, 21 Jan 2010 22:24:44 -0500 Received: from mail-pz0-f172.google.com ([209.85.222.172]:39545 "EHLO mail-pz0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753723Ab0AVDYn convert rfc822-to-8bit (ORCPT ); Thu, 21 Jan 2010 22:24:43 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=tc93Tw/X7CiZLK5KiORMvi3CGw4pT0hZTr1FHVk38JPkceshTQvcFsb+F63VNk67n7 WogRXl36as7+6Fu+UVBTSZZXGtkDTcVYguFJF0f65in7nLsX1Tj4XWuUG3USQyw5lp7T aCq9gwZzYM3C8SAlY52eSef+HCC9T3qsskuFM= MIME-Version: 1.0 In-Reply-To: <20100121155335.GB4471@osiris.boeblingen.de.ibm.com> References: <20100121155335.GB4471@osiris.boeblingen.de.ibm.com> Date: Fri, 22 Jan 2010 11:24:42 +0800 Message-ID: <7b6bb4a51001211924v12e6ebf9ve4795ce96cd0a3f8@mail.gmail.com> Subject: Re: [2.6.33-rc4] sysfs lockdep warnings on cpu hotplug From: Xiaotian Feng To: Heiko Carstens Cc: "Eric W. Biederman" , linux-kernel@vger.kernel.org, Greg KH Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3137 Lines: 67 On Thu, Jan 21, 2010 at 11:53 PM, Heiko Carstens wrote: > Hi Eric, > > rumours are that you could be responsible for the following lockdep message: > > Happens on cpu hotplug on s390: I can see the same warnings on x86_64 > > ============================================= > [ INFO: possible recursive locking detected ] > 2.6.33-rc4-00399-g24bc734 #1 > --------------------------------------------- > bash/2576 is trying to acquire lock: >  (s_active){++++.+}, at: [<000000000016c506>] sysfs_addrm_finish+0x5a/0xa8 > > but task is already holding lock: >  (s_active){++++.+}, at: [<000000000016c90c>] sysfs_get_active_two+0x64/0x88 > > other info that might help us debug this: > 5 locks held by bash/2576: >  #0:  (&buffer->mutex){+.+.+.}, at: [<000000000016a912>] sysfs_write_file+0x4a/0x1a8 >  #1:  (s_active){++++.+}, at: [<000000000016c90c>] sysfs_get_active_two+0x64/0x88 >  #2:  (s_active){++++.+}, at: [<000000000016c8e6>] sysfs_get_active_two+0x3e/0x88 >  #3:  (cpu_add_remove_lock){+.+.+.}, at: [<00000000003dd318>] cpu_down+0x44/0x88 >  #4:  (cpu_hotplug.lock){+.+.+.}, at: [<0000000000056eee>] cpu_hotplug_begin+0x3e/0x74 > > stack backtrace: > CPU: 1 Not tainted 2.6.33-rc4-00399-g24bc734 #1 > Process bash (pid: 2576, task: 000000003f0e25d0, ksp: 000000003d9339d8) > 000000003d9338b0 000000003d933830 0000000000000002 0000000000000000 >       000000003d9338d0 000000003d933848 000000003d933848 00000000003e4996 >       0000000000000000 0000000000000000 000000003f0e2cb8 0000000000835208 >       000000000000000d 000000000000000c 000000003d933898 0000000000000000 >       0000000000000000 00000000000172aa 000000003d933830 000000003d933870 > Call Trace: > ([<00000000000171b2>] show_trace+0xee/0x144) >  [<000000000008a1a0>] validate_chain+0xa2c/0x1100 >  [<000000000008ad84>] __lock_acquire+0x510/0xbfc >  [<000000000008b51c>] lock_acquire+0xac/0xd4 >  [<000000000016bba8>] sysfs_deactivate+0x94/0x108 >  [<000000000016c506>] sysfs_addrm_finish+0x5a/0xa8 >  [<0000000000169f38>] sysfs_hash_and_remove+0x64/0x9c >  [<000000000016dbae>] sysfs_remove_group+0x76/0x12c >  [<00000000003dfaae>] smp_cpu_notify+0xae/0xc8 >  [<00000000003eb652>] notifier_call_chain+0x56/0x98 >  [<000000000007a1b2>] raw_notifier_call_chain+0x2a/0x3c >  [<00000000003dd132>] _cpu_down+0x1aa/0x34c >  [<00000000003dd356>] cpu_down+0x82/0x88 >  [<00000000003ddac0>] store_online+0x5c/0xc8 >  [<000000000016a9be>] sysfs_write_file+0xf6/0x1a8 >  [<00000000000ffd5c>] vfs_write+0xac/0x178 >  [<00000000000fff24>] SyS_write+0x58/0xa8 >  [<00000000000295b6>] sysc_noemu+0x10/0x16 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html > Please read the FAQ at  http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/