Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753630AbaGHOYU (ORCPT ); Tue, 8 Jul 2014 10:24:20 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.226]:53306 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750927AbaGHOYT (ORCPT ); Tue, 8 Jul 2014 10:24:19 -0400 Date: Tue, 8 Jul 2014 10:24:16 -0400 From: Steven Rostedt To: Jiri Kosina Cc: Masami Hiramatsu , linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , "Paul E. McKenney" , Namhyung Kim , "H. Peter Anvin" , Oleg Nesterov , Josh Poimboeuf , Seth Jennings , Jiri Slaby Subject: Re: [RFC][PATCH 0/3] ftrace: Add dynamically allocated trampolines Message-ID: <20140708102416.50d996e2@gandalf.local.home> In-Reply-To: References: <20140703200750.648550267@goodmis.org> <53B6AA0C.2080704@hitachi.com> <20140704102142.7d276e4b@gandalf.local.home> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 7 Jul 2014 15:22:27 +0200 (CEST) Jiri Kosina wrote: > On Fri, 4 Jul 2014, Steven Rostedt wrote: > > > Well, I guess the answer to that is what do you consider the trampoline? > > I'm currently considering it to be the assembly code that the > > mcount/fentry call jumps to. We only have two trampolines (three if you > > count the function graph code that will be called directly come 3.17). > > Those two are the normal ftrace_caller and the ftrace_regs_caller. > > BTW, on those archs that support regs saving already, is there really a > reson not to kill ftrace_caller and keep just ftrace_regs_caller? > Consistency. Perhaps the two can be the same trampoline, which would be trivial to implement, but I wouldn't kill one which would make the generic code more complex. -- 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/