From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24306 invoked by alias); 26 Sep 2005 07:24:33 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 24164 invoked by uid 22791); 26 Sep 2005 07:24:09 -0000 Received: from ns1.lanforge.com (HELO www.lanforge.com) (66.165.47.210) by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Mon, 26 Sep 2005 07:24:09 +0000 Received: from [71.112.207.5] (pool-71-112-207-5.sttlwa.dsl-w.verizon.net [71.112.207.5]) (authenticated bits=0) by www.lanforge.com (8.12.8/8.12.8) with ESMTP id j8Q7Vbo6032574 for ; Mon, 26 Sep 2005 00:31:37 -0700 Message-ID: <4337A216.6050805@candelatech.com> Date: Mon, 26 Sep 2005 07:24:00 -0000 From: Ben Greear User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.7.10) Gecko/20050909 Fedora/1.7.10-1.3.2 MIME-Version: 1.0 To: gdb@sources.redhat.com Subject: gdb does not show full backtrace for deadlocked pthread program. Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2005-09/txt/msg00188.txt.bz2 Hello! I have a program that uses pthreads and evidently has a nifty little thread deadlock. The interesting thing is that gdb will not show me the full backtrace of the deadlocked threads. Both tested system's running a slightly modified 2.6.11 kernel. The FC2 system is a dual-xeon with SMP kernel. The FC4 machine is a laptop with UP kernel. FC2's gdb doesn't even decode frame 3, but on FC4 I get this: [after attaching to deadlocked process] (gdb) thread apply all bt Thread 2 (Thread -1208132688 (LWP 9895)): #0 0xffffe410 in ?? () #1 0xb7fd50e8 in ?? () #2 0x00000002 in ?? () #3 0x004b4e7e in __lll_mutex_lock_wait () from /lib/libpthread.so.0 Thread 1 (Thread -1208026656 (LWP 9892)): #0 0xffffe410 in ?? () #1 0xbffff118 in ?? () #2 0x00000002 in ?? () #3 0x004b4e7e in __lll_mutex_lock_wait () from /lib/libpthread.so.0 Frames 0 and 1 appear to be in linux-gate.so, most likely whatever kernel call allows nptl to work?? Any idea how to get a full backtrace for these threads? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com