From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756129AbYHRS2R (ORCPT ); Mon, 18 Aug 2008 14:28:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754024AbYHRS2F (ORCPT ); Mon, 18 Aug 2008 14:28:05 -0400 Received: from smtp1.extricom.com ([212.235.24.249]:43439 "HELO smtp.extricom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S1753921AbYHRS2F (ORCPT ); Mon, 18 Aug 2008 14:28:05 -0400 Message-ID: <48A9BEA3.10906@extricom.com> Date: Mon, 18 Aug 2008 21:25:39 +0300 From: Eran Liberty User-Agent: Thunderbird 2.0.0.14 (X11/20080502) MIME-Version: 1.0 To: Steven Rostedt CC: linux-kernel@vger.kernel.org, Mathieu Desnoyers , "Paul E. McKenney" , linuxppc-dev@ozlabs.org, rostedt@goodmis.org Subject: Re: ftrace introduces instability into kernel 2.6.27(-rc2,-rc3) References: <48591941.4070408@extricom.com> <48A92E15.2080709@extricom.com> <48A9901B.1080900@redhat.com> In-Reply-To: <48A9901B.1080900@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Steven Rostedt wrote: > Eran Liberty wrote: >> After compiling a kernel with ftrace I started to experience all >> sorts of crashes. > > Just to make sure... > > ftrace enables markers too, and RCU has tracing with the markers. This > may not be the problem, but I just want to eliminate as many variables > as possible. > Could you disable ftrace, but keep the markers on too. Also, could > you enable ftrace again and turn on the FTRACE_STARTUP_TEST. for the fun of it I took out all my propriety modules; so now its a non tainted kernel. Here is the matrix: !FTRACE x !MARKERS => stable !FTRACE x MARKERS => stable FTRACE x !MARKERS => n/a (FTRACE forces MARKERS) FTRACE x MARKERS => unstable FTRACE x FTRACE_STARTUP_TEST x MARKERS => unstable + tests passed Testing tracer sched_switch: PASSED Testing tracer ftrace: PASSED Testing dynamic ftrace: PASSED Oops: Exception in kernel mode, sig: 11 [#1] Exsw1600 Modules linked in: NIP: c00bbb20 LR: c00bbb20 CTR: 00000000 REGS: dd5b1c50 TRAP: 0700 Not tainted (2.6.27-rc2) MSR: 00029000 CR: 24082282 XER: 20000000 TASK = ddcce060[1707] 'find' THREAD: dd5b0000 GPR00: 00000000 dd5b1d00 ddcce060 dd801180 dd5b1d68 dd5b1d58 dd80125b 100234ec GPR08: c0800000 00019330 0000ffff dd5b1d20 24000288 100ad874 100936f8 1008a1d0 GPR16: 10083f80 dd5b1e2c dd5b1d68 fffffff4 c0380000 dd5b1d60 dd5b1d58 dd802084 GPR24: dc3d7700 dd802018 dd5b1d68 c0380000 dd801180 dd5b1d68 00000000 dd5b1d00 NIP [c00bbb20] d_lookup+0x40/0x90 LR [c00bbb20] d_lookup+0x40/0x90 Call Trace: [dd5b1d00] [dd5b1d58] 0xdd5b1d58 (unreliable) [dd5b1d20] [c00aebc4] do_lookup+0xe8/0x220 [dd5b1d50] [c00b0a80] __link_path_walk+0x5a4/0xd54 [dd5b1dc0] [c00b1288] path_walk+0x58/0xe0 [dd5b1df0] [c00b13f8] do_path_lookup+0x78/0x13c [dd5b1e20] [c00b20f4] user_path_at+0x64/0xac [dd5b1e90] [c00a9028] vfs_lstat_fd+0x34/0x74 [dd5b1ec0] [c00a90fc] vfs_lstat+0x30/0x48 [dd5b1ed0] [c00a9144] sys_lstat64+0x30/0x5c [dd5b1f40] [c0010554] ret_from_syscall+0x0/0x3c Instruction dump: 7c0802a6 bf61000c 3f60c038 7c3f0b78 90010024 7c7c1b78 7c9d2378 83db32a0 73c00001 7f83e378 7fa4eb78 4082002f <00000000> 2f830000 409e0030 801b32a0 ---[ end trace 1eb8fd7adac2bb65 ]--- Liberty