Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752371Ab2E3Gjd (ORCPT ); Wed, 30 May 2012 02:39:33 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:42049 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750866Ab2E3Gjc (ORCPT ); Wed, 30 May 2012 02:39:32 -0400 X-AuditID: b753bd60-92bfeba000003d24-1a-4fc5c0a0a5eb X-AuditID: b753bd60-92bfeba000003d24-1a-4fc5c0a0a5eb Message-ID: <4FC5C09C.6030703@hitachi.com> Date: Wed, 30 May 2012 15:39:24 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Ananth N Mavinakayanahalli , "Frank Ch. Eigler" , Andrew Morton , Frederic Weisbecker , yrl.pp-manager.tt@hitachi.com Subject: Re: [RFC PATCH -tip 2/9] ftrace/x86-64: support SAVE_REGS feature on x86-64 References: <20120529124833.9191.23007.stgit@localhost.localdomain> <20120529124905.9191.91563.stgit@localhost.localdomain> <1338332727.13348.301.camel@gandalf.stny.rr.com> In-Reply-To: <1338332727.13348.301.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1149 Lines: 31 (2012/05/30 8:05), Steven Rostedt wrote: > No! Please do not make ftrace save all regs for everyone. This is > critical. This will slow down function tracing even more. We do not need > to save all regs for every function call, unless it is asked for. Indeed, I have just removed your save_regs dynamic selector code, because I'd like to make this series as simple as possible for review. > It should only save all regs if the ftrace_ops that is registered asked > for it. I had code that actually does that. I can merge your patches > with them if you would like. Yes, I'd like :) BTW, that code which dynamically selects trace_caller on your ftrace-v2 tree, seems to be an uncompleted work. Would you already have done it? Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: 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/