Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757943AbYJTRVv (ORCPT ); Mon, 20 Oct 2008 13:21:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754613AbYJTRJt (ORCPT ); Mon, 20 Oct 2008 13:09:49 -0400 Received: from ey-out-2122.google.com ([74.125.78.24]:46817 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752970AbYJTRJp (ORCPT ); Mon, 20 Oct 2008 13:09:45 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent:sender; b=xzAS2Rt5yTbjNIZsBRaFU+yBiqX5doxzJPO6xs5G8JWmrb73FAo6qorpbWnN6LFYMT bAl3Tnj5A2EsD2FmIaZGsdAgZOMzDqXVHjngAIOe60Q7h+n75OUQSIaogVo6WcIfNcoY AmxGg+Dw7VuSvR/HlHG0IB5Qx6kaKIojZI0uc= Date: Mon, 20 Oct 2008 13:08:08 -0400 From: Josh Boyer To: Steven Rostedt Cc: Andrew Morton , Peter Zijlstra , linux-kernel@vger.kernel.org, David Miller , linuxppc-dev@ozlabs.org, Ingo Molnar , Thomas Gleixner Subject: Re: [PATCH 0/2] ftrace: fixes for PPC Message-ID: <20081020170808.GB7249@yoda.jdub.homelinux.org> References: <20080906050602.409299112@goodmis.org> <20080906120346.GA30964@elte.hu> <20081016181452.GA29739@yoda.jdub.homelinux.org> <20081016183529.GB29739@yoda.jdub.homelinux.org> <20081016150106.6ddf7e46@zod.rchland.ibm.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: 1437 Lines: 31 On Mon, Oct 20, 2008 at 12:30:33PM -0400, Steven Rostedt wrote: >> Anyway, if you want a tester let me know. It seems 2.6.27.1 should be >> fine since FTRACE was disabled, but for .28-rc1 it would be cool if it >> worked :). > >Hi Josh, > >I've been looking deeper at the code for PPC. I realized that my PPC64 box >that I've been testing on did not use modules. While looking at the module >code it dawned on me the dynamic ftrace needs a bit of work. This is >because the way modules are handled in PPC (and other architectures as >well). The jmps used by mcount is a 24 bit jump. Since the modules are >loaded farther than 24bits away, a trampoline is needed. Ah, indeed. >A bit of rework is needed in the ftrace infrastructure to handle the >trampoline. Too much work to go into 28. I'll start working on code that >can hopefully be ready and tested for 29. It's not that major of a change, >but since the merge window for 28 has already been opened, we would like >to get a bit more testing in before we hand it over to Linus. That seems like a good plan. Should we mark dynamic ftrace as X86 only in Kconfig for .28 to prevent people from inadvertently setting it? josh -- 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/