Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755140AbZDGEhb (ORCPT ); Tue, 7 Apr 2009 00:37:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751311AbZDGEhV (ORCPT ); Tue, 7 Apr 2009 00:37:21 -0400 Received: from rv-out-0506.google.com ([209.85.198.234]:49195 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929AbZDGEhT convert rfc822-to-8bit (ORCPT ); Tue, 7 Apr 2009 00:37:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=fXkNXv+8LTq6dkRargfLEDAZERdH/kqFgxlbHmJNDzWaGm/1ARqF/9Hgq6Ly8l8jkh iKMsr/MhIYGAU3eLpusY9GJCgrzOP5SmPw/BD7Lk5H2zul8BBDjb6Ugbq74aH7JpQr8d nC027mJydDf/4Dqtjb/LfdJUg+61uA4qa3ZDQ= MIME-Version: 1.0 In-Reply-To: <1239067616.4753.12.camel@localhost.localdomain> References: <49b7c2350904060702j3f725a45ub5e7d3ee3af883c1@mail.gmail.com> <49b7c2350904060717l1a87cca7p880b6843ea92c702@mail.gmail.com> <1239067616.4753.12.camel@localhost.localdomain> Date: Tue, 7 Apr 2009 13:37:17 +0900 Message-ID: <49b7c2350904062137p46661ad8s11c9c2a31e367329@mail.gmail.com> Subject: Re: [PATCH] Update old Mini-HOWTO for ftrace From: GeunSik Lim To: Steven Rostedt Cc: Ingo Molnar , rt-users , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3778 Lines: 101 > What's the chrt for? We often need simple test to get latency result of realtime using "current_tracers" file. In this case, We can run easy testcase as realtime task with the chrt command. Although we usually use function tracer for tracing internal kernel functions by ftraced. I think that we need simple example like the chrt for monitoring latencies and the kernel functoins using sleep command as realtime task. 2009/4/7 Steven Rostedt : > > On Mon, 2009-04-06 at 23:17 +0900, GeunSik Lim wrote: >> I attached patch file again because no-operation is changed >> from "none"word to "nop" word. >> >> for example, >> -       "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" >> +       "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n" >> >> ./trace_nop.c:struct tracer nop_trace __read_mostly = >>       .name   = "nop", >>       .init           = nop_trace_init, >>       .reset  = nop_trace_reset, >>       .selftest       = trace_selftest_startup_nop, >>       .flags  = &nop_flags, >>       .set_flag       = nop_set_flag >> >> >> >> 2009/4/6 GeunSik Lim : >> >   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" > > > What's the chrt for? > > -- Steve > > > -- Regards, GeunSik Lim -- 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/ -- 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/