Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754054AbbKBRjq (ORCPT ); Mon, 2 Nov 2015 12:39:46 -0500 Received: from mga02.intel.com ([134.134.136.20]:41671 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752466AbbKBRjn (ORCPT ); Mon, 2 Nov 2015 12:39:43 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,234,1444719600"; d="scan'208";a="840807409" Subject: Re: [lkp] [fs] df4c0e36f1: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1] To: Andrey Ryabinin , kernel test robot References: <87611kakr3.fsf@yhuang-dev.intel.com> Cc: LKP , LKML , Andrew Morton , David Rientjes , Pekka Enberg , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Andi Kleen , Joonsoo Kim , Christoph Lameter , Sasha Levin , Konstantin Khlebnikov , Yuri Gribov , Andrey Konovalov , Dmitry Chernenkov , Konstantin Serebryany , Dmitry Vyukov , Linus Torvalds From: Dave Hansen Message-ID: <56379FDE.6010603@intel.com> Date: Mon, 2 Nov 2015 09:39:42 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 999 Lines: 29 On 11/02/2015 01:32 AM, Andrey Ryabinin wrote: > And the major factor here is number 2. > > In your dmesg: > [ 67.891156] rbtree testing -> 570841 cycles > [ 88.609636] augmented rbtree testing > [ 116.546697] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! > [swapper/0:1] > > > I've tried to reproduce this, and got this: > [ 0.693574] rbtree testing -> 15513 cycles > 570841/15513 = 36x times faster. > > [ 1.159450] augmented rbtree testing -> 23675 cycles > [ 1.864996] > It took less than a second, meanwhile in your case it didn't finish in > 22 seconds. > > This makes me think that your host is overloaded and the problem is on > your side. It's probably just a matter of putting some cond_resched()s in the test code. -- 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/