From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [PATCH] Update old Mini-HOWTO for ftrace Date: Mon, 06 Apr 2009 21:46:52 -0400 Message-ID: <1239068812.4753.15.camel@localhost.localdomain> References: <49b7c2350904060702j3f725a45ub5e7d3ee3af883c1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Ingo Molnar , rt-users , "linux-kernel@vger.kernel.org" , Nikanth Karthikensan To: GeunSik Lim Return-path: Received: from mx2.redhat.com ([66.187.237.31]:33649 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751621AbZDGBrH (ORCPT ); Mon, 6 Apr 2009 21:47:07 -0400 In-Reply-To: <49b7c2350904060702j3f725a45ub5e7d3ee3af883c1@mail.gmail.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 2009-04-06 at 23:02 +0900, GeunSik Lim wrote: > Dear Steven, > > The author of ftrace(Internal kernel Function Tracer) feature > renamed the ftrace tracer > to function to avoid further confusion between the ftrace > infrastructure and the > function tracer on Oct-20, 2008. > > But, Update of Mini-HOWTO document are still not working > . > Most of the developers often utilize "/debug/tracing/README" file > as Mini-HOWTO. > They will confuse definition and usage about ftrace between > README(ftrace) file > and available_tracers(function) file after linux-2.6.27 like me. > And, I want you to append "chrt -f 5 sleep 1" command as simple > example for latency. > > Signed-off-by: GeunSik Lim > Signed-off-by: Steven Rostedt > Signed-off-by: Ingo Molnar > --- > kernel/trace/trace.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index a0174a4..15f0eec 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -2358,7 +2358,7 @@ static const char readme_msg[] = > "# mkdir /debug\n" > "# mount -t debugfs nodev /debug\n\n" > "# cat /debug/tracing/available_tracers\n" > - "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" > + "wakeup preemptirqsoff preemptoff irqsoff function > sched_switch none\n\n" > "# cat /debug/tracing/current_tracer\n" > "none\n" > "# echo sched_switch > /debug/tracing/current_tracer\n" > @@ -2368,6 +2368,7 @@ static const char readme_msg[] = > "noprint-parent nosym-offset nosym-addr noverbose\n" > "# echo print-parent > /debug/tracing/trace_options\n" > "# echo 1 > /debug/tracing/tracing_enabled\n" > + "# chrt -f 5 sleep 1\n" > "# cat /debug/tracing/trace > /tmp/trace.txt\n" > "echo 0 > /debug/tracing/tracing_enabled\n" > ; > Actually Nikanth sent a similar patch a month ago, but somehow it slipped under the radar. I'll be picking that one up instead. http://lkml.org/lkml/2009/3/23/24 But thanks anyway. -- Steve