Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753929Ab3GYBYM (ORCPT ); Wed, 24 Jul 2013 21:24:12 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:9121 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752668Ab3GYBYI (ORCPT ); Wed, 24 Jul 2013 21:24:08 -0400 X-Authority-Analysis: v=2.0 cv=KJ7Y/S5o c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=_6S4gJz81GoA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=UirpL7NoV14A:10 a=JnOv4dvnuGwhp6quMyYA:9 a=QEXdDO2ut3YA:10 a=DdYowudkXfDnKeFB:21 a=ng-RXzEF0Hg5XBQj:21 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-ID: <1374715444.3356.163.camel@gandalf.local.home> Subject: Re: __ftrace_hash_rec_update FTRACE_WARN_ON. From: Steven Rostedt To: =?ISO-8859-1?Q?J=F6rn?= Engel Cc: Dave Jones , linux-kernel@vger.kernel.org, steve@purestorage.com Date: Wed, 24 Jul 2013 21:24:04 -0400 In-Reply-To: <20130724160422.GA3641@logfs.org> References: <20130705142629.GA325@redhat.com> <1373036034.22688.155.camel@gandalf.local.home> <20130724160422.GA3641@logfs.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-3 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3561 Lines: 57 On Wed, 2013-07-24 at 12:04 -0400, Jörn Engel wrote: > On Fri, 5 July 2013 10:53:54 -0400, Steven Rostedt wrote: > > > > Can you find an easy reproducer for this? > > We might have found something: > > Jul 23 19:00:59 [28253.487058,08] WARNING: at kernel/trace/ftrace.c:1529 __ftrace_hash_rec_update+0x1e3/0x230() > Jul 23 19:00:59 [28253.487203,08] Pid: 20903, comm: bash Tainted: G O 3.6.11+ #38405.trunk > Jul 23 19:00:59 [28253.487206,08] Call Trace: > Jul 23 19:00:59 [28253.487213,08] [] warn_slowpath_common+0x7f/0xc0 > Jul 23 19:00:59 [28253.487218,08] [] warn_slowpath_null+0x1a/0x20 > Jul 23 19:00:59 [28253.487222,08] [] __ftrace_hash_rec_update+0x1e3/0x230 > Jul 23 19:00:59 [28253.487227,08] [] ftrace_hash_move+0x28/0x1d0 > Jul 23 19:00:59 [28253.487232,08] [] ? kfree+0x2c/0x110 > Jul 23 19:00:59 [28253.487237,08] [] ftrace_regex_release+0x8e/0x150 > Jul 23 19:00:59 [28253.487242,08] [] __fput+0xae/0x220 > Jul 23 19:00:59 [28253.487247,08] [] ____fput+0xe/0x10 > Jul 23 19:00:59 [28253.487252,08] [] task_work_run+0x72/0x90 > Jul 23 19:00:59 [28253.487257,08] [] do_notify_resume+0x6c/0xc0 > Jul 23 19:00:59 [28253.487262,08] [] ? trace_hardirqs_on_thunk+0x3a/0x3c > Jul 23 19:00:59 [28253.487267,08] [] int_signal+0x12/0x17 > Jul 23 19:00:59 [28253.487271,08] ---[ end trace 793179526ee09b2c ]--- > > Jul 23 19:21:02 [ 775.393547,08] WARNING: at kernel/trace/ftrace.c:1529 __ftrace_hash_rec_update+0x1e3/0x230() > Jul 23 19:21:02 [ 775.393715,08] Pid: 6376, comm: bash Tainted: G O 3.6.11+ #38405.trunk > Jul 23 19:21:02 [ 775.393718,08] Call Trace: > Jul 23 19:21:02 [ 775.393727,08] [] warn_slowpath_common+0x7f/0xc0 > Jul 23 19:21:02 [ 775.393732,08] [] warn_slowpath_null+0x1a/0x20 > Jul 23 19:21:02 [ 775.393737,08] [] __ftrace_hash_rec_update+0x1e3/0x230 > Jul 23 19:21:02 [ 775.393741,08] [] ftrace_hash_move+0x28/0x1d0 > Jul 23 19:21:02 [ 775.393748,08] [] ? kfree+0x2c/0x110 > Jul 23 19:21:02 [ 775.393754,08] [] ftrace_regex_release+0x8e/0x150 > Jul 23 19:21:02 [ 775.393771,08] [] __fput+0xae/0x220 > Jul 23 19:21:02 [ 775.393784,08] [] ____fput+0xe/0x10 > Jul 23 19:21:02 [ 775.393792,08] [] task_work_run+0x72/0x90 > Jul 23 19:21:02 [ 775.393798,08] [] do_notify_resume+0x6c/0xc0 > Jul 23 19:21:02 [ 775.393804,08] [] ? trace_hardirqs_on_thunk+0x3a/0x3c > Jul 23 19:21:02 [ 775.393810,08] [] int_signal+0x12/0x17 > Jul 23 19:21:02 [ 775.393814,08] ---[ end trace 3b86cc549cc5483e ]--- > > If I understand Steve correctly, you have to enable a trace somewhere > in a module, them rmmod that module without disabling the trace. Easy > enough to avoid, but maybe you are interested. I'm a bit confused by this. What do you mean exactly by enable a trace somewhere in a module? The module enables the trace? Does it have its own ftrace_ops? Or the module just starts tracing? -- Steve -- 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/