Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752540AbaKDCaf (ORCPT ); Mon, 3 Nov 2014 21:30:35 -0500 Received: from mailout32.mail01.mtsvc.net ([216.70.64.70]:36084 "EHLO n23.mail01.mtsvc.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751322AbaKDCaa (ORCPT ); Mon, 3 Nov 2014 21:30:30 -0500 Message-ID: <54583A43.2000303@hurleysoftware.com> Date: Mon, 03 Nov 2014 21:30:27 -0500 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Steven Rostedt CC: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] ftrace: Document ftrace command line limitations References: <1415065525-8267-1-git-send-email-peter@hurleysoftware.com> <20141103211431.0d8a80b8@gandalf.local.home> In-Reply-To: <20141103211431.0d8a80b8@gandalf.local.home> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Authenticated-User: 990527 peter@hurleysoftware.com X-MT-ID: 8FA290C2A27252AACF65DBC4A42F3CE3735FB2A4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/03/2014 09:14 PM, Steven Rostedt wrote: > On Mon, 3 Nov 2014 20:45:25 -0500 > Peter Hurley wrote: > >> When using the function or function_graph tracers from the command >> line, certain command line options have limitations. >> >> Document that only kernel built-in functions can be filtered via >> ftrace_filter= or ftrace_graph_filter=. Also document that tracer- >> specific options cannot be set on the command line via trace_options. > > It's not just a command line limitation. The command line behaves > exactly like set_ftrace_filter does. That is, it only affects the > functions that are loaded when the filter is modified. It never updates > functions that will be loaded when modules are. > > Adding this documentation makes it seem that set_ftrace_filter has the > ability to update functions that were not loaded yet. This is not true. > The command line filtering behaves exactly like set_ftrace_filter does. > It only enables the functions that are loaded at the time the function > is set. Which was at boot up, and it just happens to be only built in > functions at that time. Ah, ok. I'll clarify those two lines and add to the documentation in Documentation/trace/ftrace.txt -- 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/