From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751862AbaI3NDl (ORCPT ); Tue, 30 Sep 2014 09:03:41 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.227]:30044 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750908AbaI3NDk (ORCPT ); Tue, 30 Sep 2014 09:03:40 -0400 Date: Tue, 30 Sep 2014 09:03:31 -0400 From: Steven Rostedt To: Amit Virdi Cc: fweisbec@gmail.com, mingo@redhat.com, linux-kernel@vger.kernel.org Subject: Re: Enabling ftrace on ARM MMU-less system Message-ID: <20140930090331.15a7b428@gandalf.local.home> In-Reply-To: References: X-Mailer: Claws Mail 3.10.1 (GTK+ 2.24.24; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.142:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Sep 2014 16:26:49 +0530 Amit Virdi wrote: > Hi, > > I'm trying to enable Ftrace on my ARM based MMU-less system. > Unexpectedly, I don't see tracing directory under /sys/kernel/debug > I have done the following so far but no success: > 1. Verified that I have enabled these flags in my .config > CONFIG_FUNCTION_TRACER > CONFIG_FUNCTION_GRAPH_TRACER > CONFIG_STACK_TRACER > CONFIG_DYNAMIC_FTRACE > > 2. Enabled Ftrace startup steps. The startup log output is > ---- > > Can anyone help what I'm missing or if ftrace is supported on MMU-less > platforms? Well it's obviously supported if you see the tests running. Is there anything else under /sys/kernel/debug? If not you need to mount the debugfs filesytem there. It wont do it itself. # mount -t debugfs nodev /sys/kernel/debug -- Steve