Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754134AbYJaCFu (ORCPT ); Thu, 30 Oct 2008 22:05:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753077AbYJaCFk (ORCPT ); Thu, 30 Oct 2008 22:05:40 -0400 Received: from mail.atheros.com ([12.36.123.2]:47715 "EHLO mail.atheros.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752496AbYJaCFj (ORCPT ); Thu, 30 Oct 2008 22:05:39 -0400 Date: Thu, 30 Oct 2008 19:05:37 -0700 From: "Luis R. Rodriguez" To: Steven Rostedt CC: "Luis R. Rodriguez" , Tim Gardner , Tomas Winkler , reinette chatre , "linux-wireless@vger.kernel.org" , Linux-Kernel Subject: Re: [MEMO] ftrace suckage++ Message-ID: <20081031020537.GJ21459@tesla> References: <43e72e890810301445r665a0139g752fb1c97069fe59@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1935 Lines: 46 On Thu, Oct 30, 2008 at 06:54:00PM -0700, Steven Rostedt wrote: > > On Thu, 30 Oct 2008, Luis R. Rodriguez wrote: > > > As johannes pointed out to me the culprit to the e1000e corruption was > > determined to be ftrace related [1]. Well it seems I hit an oops with > > ftrace using iwlagn after a simple load of the module using > > wireless-testing. I'm not sure if john's tree yet has ftrace fixes. > > Both Fedora 10 and Ubuntu 8.10 had dynamic ftrace enabled so users on > > these first kernels and using compat-wireless may run into this so > > just putting this out there. I'll can check for this flag in > > compat-wireless for now and bitch/exit if its enabled unless someone > > has a better idea. > > > > [1] http://lwn.net/Articles/303390/ > > > > Oops, using wireless-testing and iwlagn with these options enabled: > > > > CONFIG_HAVE_FTRACE=y > > CONFIG_HAVE_DYNAMIC_FTRACE=y > > CONFIG_FTRACE=y > > CONFIG_DYNAMIC_FTRACE=y > > > > Yes, ftrace in 2.6.27 is known to be broken. That's why 2.6.27.1 labeled > it as such. What is currently in Linus's 2.6.28 git tree is a completely > rewritten version of the dynamic ftracer, which addresses all of the > issues that caused breakage in the 2.6.27 release. > > Do not use the 2.6.27 dynamic ftracer, it is known bad. 2.6.28 is fine. If > you find issues with what is currently in 2.6.28, please let me know. > There is currently some, "make allyesconfig" breakage that ftrace caused > on archs other than x86,ppc and sparc, but patches to fix them are > in queue to Linus. OK then in that case if *and only if* on 27 and if dynamic tracer is enabled I'll set compat stuff to simply bail out at compile time. Thanks, Luis -- 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/