Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262507AbVD2MJS (ORCPT ); Fri, 29 Apr 2005 08:09:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262512AbVD2MJS (ORCPT ); Fri, 29 Apr 2005 08:09:18 -0400 Received: from fire.osdl.org ([65.172.181.4]:39371 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S262507AbVD2MJN (ORCPT ); Fri, 29 Apr 2005 08:09:13 -0400 Date: Fri, 29 Apr 2005 05:08:33 -0700 From: Andrew Morton To: "Pedro Venda (SYSADM)" Cc: linux-kernel@vger.kernel.org, rnl@rnl.ist.utl.pt Subject: Re: ftp server crashes on heavy load: possible scheduler bug Message-Id: <20050429050833.6b3d805b.akpm@osdl.org> In-Reply-To: <200504261402.57375.pjvenda@rnl.ist.utl.pt> References: <200504261402.57375.pjvenda@rnl.ist.utl.pt> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1627 Lines: 42 "Pedro Venda (SYSADM)" wrote: > > We've made some changes on our ftp server, and since that it's been crashing > frequently (everyday) with a kernel panic. > > We've configured the 5 IDE 160GB drives into md raid5 arrays with LVM on top > of that. All filesystems are reiserfs. The other change we made to the server > was changing from a patched 2.6.10-ac12 kernel into a newer 2.6.11.7. > > Not being able to see the whole stacktrace on screen, we've started a > netconsole to investigate. Started the server and loaded it pretty bad with > rsyncs and such... until it crashed after just 20 minutes. > > The netconsole log was surprising - "kernel BUG at kernel/sched.c:2634!" Strange. It'd be interesting to try disabling CONFIG_4KSTACKS. Also, please add this to get a bit more info. diff -puN kernel/sched.c~a kernel/sched.c --- 25/kernel/sched.c~a 2005-04-29 05:05:24.792004408 -0700 +++ 25-akpm/kernel/sched.c 2005-04-29 05:06:36.015176840 -0700 @@ -2631,7 +2631,12 @@ void fastcall add_preempt_count(int val) /* * Underflow? */ - BUG_ON(((int)preempt_count() < 0)); + if ((int)preempt_count() < 0) { + printk("preempt_count=%d\n", preempt_count()); + BUG(); + } + if ((int)preempt_count() > 1000) + printk("preempt_count=%d\n", preempt_count()); preempt_count() += val; /* * Spinlock count overflowing soon? _ - 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/