From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263807AbUEOFkW (ORCPT ); Sat, 15 May 2004 01:40:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264645AbUEOFkW (ORCPT ); Sat, 15 May 2004 01:40:22 -0400 Received: from taco.zianet.com ([216.234.192.159]:53008 "HELO taco.zianet.com") by vger.kernel.org with SMTP id S263807AbUEOFkJ convert rfc822-to-8bit (ORCPT ); Sat, 15 May 2004 01:40:09 -0400 From: Steven Cole To: Andrew Morton Subject: Re: 1352 NUL bytes at the end of a page? (was Re: Assertion `s && s->tree' failed: The saga continues.) Date: Fri, 14 May 2004 23:39:37 -0600 User-Agent: KMail/1.6.1 Cc: Lincoln Dale , adi@bitmover.com, scole@lanl.gov, support@bitmover.com, torvalds@osdl.org, linux-kernel@vger.kernel.org References: <200405132232.01484.elenstev@mesatop.com> <5.1.0.14.2.20040515130250.00b84ff8@171.71.163.14> <20040514204153.0d747933.akpm@osdl.org> In-Reply-To: <20040514204153.0d747933.akpm@osdl.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-Id: <200405142339.38059.elenstev@mesatop.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 14 May 2004 09:41 pm, Andrew Morton wrote: > Lincoln Dale wrote: > > > > At 02:53 AM 15/05/2004, Andy Isaacson wrote: > > >That corruption size really does make me think of network packets, so > > >I'm tempted to blame it on PPP. Can you find out the MTU of your PPP > > >link? "ifconfig ppp0" or something like that. > > > > 1352 bytes coule be remarkably close to the TCP MSS . . . > > perhaps there is some interaction with ppp where there is an overrun / lost > > packet and the TCP window is mistakenly advanced? > > Steve, if it's a memory stomp then perhaps CONFIG_DEBUG_PAGEALLOC and > CONFIG_DEBUG_SLAB might pick it up. > > It seems awfully deterministic though. > > Andy asked me to do the following without ppp, which I did. The explanation of the odd key is in his previous mail. #!/bin/sh x=0 while true; do         bk clone -qlr40514130hBbvgP4CvwEVEu27oxm46w testing-2.6 foo         (cd foo; bk pull -q)         rm -rf foo         x=`expr $x + 1`         echo -n "$x " done The above caused a failure after the 7th iteration or so. This time, the RESYNC/SCCS/s.ChangeSet file didn't have any nulls, but three other files did, namely s.Makefile, s.CREDITS, s.MAINTAINERS. Not knowing whether this was normal or not, I've sent those files to bitkeeper for analysis. Since I only began seeing these "Assertion `s && s->tree' failed" problems with bk in the past month or so, and I generally run a current kernel on this machine, I booted an older kernel, 2.6.3. I'm going to run Andy's test overnight and see if 2.6.3 acts any differently. In the meantime, I'll have the machine building a 2.6.6-plus kernel with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_SLAB if its use seems indicated in the morning. Steven