From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21656 invoked by alias); 18 May 2009 13:49:49 -0000 Received: (qmail 21642 invoked by uid 22791); 18 May 2009 13:49:47 -0000 X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from mail-out.m-online.net (HELO mail-out.m-online.net) (212.18.0.10) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 18 May 2009 13:49:41 +0000 Received: from mail01.m-online.net (mail.m-online.net [192.168.3.149]) by mail-out.m-online.net (Postfix) with ESMTP id B6F7E1C00156; Mon, 18 May 2009 15:49:38 +0200 (CEST) Received: from localhost (dynscan2.mnet-online.de [192.168.1.215]) by mail.m-online.net (Postfix) with ESMTP id 837F09025A; Mon, 18 May 2009 15:49:38 +0200 (CEST) Received: from mail.mnet-online.de ([192.168.3.149]) by localhost (dynscan2.mnet-online.de [192.168.1.215]) (amavisd-new, port 10024) with ESMTP id oUgrHfWQUGac; Mon, 18 May 2009 15:49:37 +0200 (CEST) Received: from igel.home (DSL01.83.171.162.149.ip-pool.NEFkom.net [83.171.162.149]) by mail.mnet-online.de (Postfix) with ESMTP; Mon, 18 May 2009 15:49:37 +0200 (CEST) Received: by igel.home (Postfix, from userid 501) id 2FF4510C56A; Mon, 18 May 2009 15:49:37 +0200 (CEST) From: Andreas Schwab To: psmith@gnu.org Cc: Andi Kleen , gdb@sourceware.org Subject: Re: Partial cores using Linux "pipe" core_pattern References: <1242609756.2800.135.camel@homebase.localnet> <87ab5aq3dq.fsf@basil.nowhere.org> <1242653371.2800.163.camel@homebase.localnet> X-Yow: Did you move a lot of KOREAN STEAK KNIVES this trip, Dingy? Date: Mon, 18 May 2009 13:49:00 -0000 In-Reply-To: <1242653371.2800.163.camel@homebase.localnet> (Paul Smith's message of "Mon, 18 May 2009 09:29:31 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.93 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2009-05/txt/msg00117.txt.bz2 Paul Smith writes: > On Mon, 2009-05-18 at 09:25 +0200, Andi Kleen wrote: >> Paul Smith writes: >> > >> > Does anyone have any thoughts about where I can look next to try to >> > figure out what's going on? Ideas or knowledge about limitations of the >> > kernel's core_pattern pipe capability, such as timing issues etc., that >> > might be leaving me with short cores? >> >> Sounds more like a kernel problem to me. It would be good if you >> could find out in what way the cores are truncated, then do a proper >> kernel bug report. >> >> Or add printks to the kernel coredumper and try to figure out this >> way where/why it stops. > > Heh, I was afraid you'd say that :-). OK, I'll dig into the kernel > coredumper and add some printks etc. Apparently the ELF core dumper cannot handle short writes (see dump_write in fs/binfmt_elf.c). You should probably use a read buffer of at least a page, which is the most the kernel tries to write at once. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."