Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754803AbYJQBFF (ORCPT ); Thu, 16 Oct 2008 21:05:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752074AbYJQBEy (ORCPT ); Thu, 16 Oct 2008 21:04:54 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:64857 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004AbYJQBEy (ORCPT ); Thu, 16 Oct 2008 21:04:54 -0400 Date: Thu, 16 Oct 2008 21:04:51 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Benjamin Herrenschmidt cc: Josh Boyer , Andrew Morton , Peter Zijlstra , linux-kernel@vger.kernel.org, David Miller , linuxppc-dev@ozlabs.org, Ingo Molnar , Thomas Gleixner Subject: Re: [PATCH] ftrace: powerpc: remove startup functions from tracing In-Reply-To: <1224204646.7654.52.camel@pasglop> Message-ID: References: <20080906050602.409299112@goodmis.org> <20080906120346.GA30964@elte.hu> <20081016181452.GA29739@yoda.jdub.homelinux.org> <1224204646.7654.52.camel@pasglop> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1488 Lines: 37 On Fri, 17 Oct 2008, Benjamin Herrenschmidt wrote: > On Thu, 2008-10-16 at 20:48 -0400, Steven Rostedt wrote: > > > > The early init code in PowerPC is not mapped to their final locations > > and all jumps and memory references must be done with relative jumps > > and accesses. > > > > The lib files in the powerpc directory are called in early boot, and > > since mcount will perform direct access to memory, the lib files need > > not be traced. > > This is annoying though, because that means things like memcpy, > copy_to_from_user etc... can't be traced. On the other hand a lot > of that is asm and already doesn't call mcount. Yeah, I know. I was going to pick and choose which files in there should be converted, but then I saw that they were mostly asm, and it seemed to be better safe than sorry. Sure, we could probably bring it down a bit. But I'm a bit paranoid it may cause someone else not to boot because of something else being called at early boot up. But don't worry. When we get MCOUNT_RECORD ported to PPC this no longer becomes an issue, and we can simply do a "ifndef CONFIG_FTRACE_MCOUNT_RECORD" around the -pg removal in the Makefile. (or what ever the Makefile syntax is for config options) -- 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/