Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757138AbXL3Oxi (ORCPT ); Sun, 30 Dec 2007 09:53:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755299AbXL3Oxb (ORCPT ); Sun, 30 Dec 2007 09:53:31 -0500 Received: from mx1.redhat.com ([66.187.233.31]:58759 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755226AbXL3Oxa (ORCPT ); Sun, 30 Dec 2007 09:53:30 -0500 Message-ID: <4777B0AA.9050503@redhat.com> Date: Sun, 30 Dec 2007 09:52:26 -0500 From: Masami Hiramatsu User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Ingo Molnar , Ananth N Mavinakayanahalli CC: Harvey Harrison , Jim Keniston , LKML , "H. Peter Anvin" , Thomas Gleixner Subject: Re: [PATCH] x86: kprobes remove fix_riprel #ifdef References: <1198466917.6323.15.camel@brick> <47773CAD.7050907@redhat.com> <20071230132337.GF16946@elte.hu> In-Reply-To: <20071230132337.GF16946@elte.hu> X-Enigmail-Version: 0.95.5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1488 Lines: 49 Hello Ingo, Ingo Molnar wrote: > * Masami Hiramatsu wrote: > >> Hello Harvey, >> >> A similar idea was already nack-ed by Ananth. >> http://sources.redhat.com/ml/systemtap/2007-q4/msg00468.html >> And I agree his thought. >> >> Especially, "riprel" does not exist on x86_32, so fix_riprel() >> is meaningless on it. >> Thus, I think it would better be ifdef'd in call-site. > > but we regularly do this in generic code: we add calls that are NOPs on > some architectures. For example flush_cache_page() makes no sense on the > x86 architecture. Indeed. By the way, flush_cache_page() is defined as a do-while(0) on x86. Would it better to define fix_riprel() as a do-while(0) on x86-32? I think this obviously indicates that function has no effect. > So i'm inclined to apply Harvey's cleanup - less > #ifdef complexity in higher-level code is very much favored, even > if "riprel" is a NOP concept on 32-bit. OK, I agree about that fix_riprel() which is ifdef'd twice is too much ifdef'd. Reducing ifdef is good to me. Thanks, > > Ingo -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: mhiramat@redhat.com, masami.hiramatsu.pt@hitachi.com -- 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/