From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754238Ab3H2PML (ORCPT ); Thu, 29 Aug 2013 11:12:11 -0400 Received: from mail-qa0-f53.google.com ([209.85.216.53]:38483 "EHLO mail-qa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752673Ab3H2PMJ (ORCPT ); Thu, 29 Aug 2013 11:12:09 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 29 Aug 2013 20:42:08 +0530 Message-ID: Subject: Re: wakeup tracer not able to capture traces on 3.4 kernel From: Prabhat Kumar Ravi To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 29, 2013 at 7:41 PM, Prabhat Kumar Ravi wrote: > Hi, > > I trying to capture traces through wakeup tracer, but not able to > capture it on 3.4 kernel with cortex A9 processor, armv7. > {{{ > / # mount -t debugfs nodev /debug > / # sysctl kernel.ftrace_enabled=1 > kernel.ftrace_enabled = 1 > / # echo wakeup > /debug/tracing/current_tracer > / # echo latency-format > /debug/tracing/trace_options > / # echo 0 > /debug/tracing/tracing_max_latency > / # echo 1 > /debug/tracing/tracing_on > / # sleep 10 > / # echo 0 > /debug/tracing/tracing_on > / # cat /debug/tracing/trace > # tracer: wakeup > # > }}} My target board is xilinx-zc702, here in kernel/trace/trace.c: void tracing_record_cmdline(struct task_struct *tsk) { if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled || !tracing_is_on()) -------------------------------> it not coming here at all. return; trace_save_cmdline(tsk); } Regards, Prabhat