linux-kernel - Re: [PATCH] Update old Mini-HOWTO for ftrace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1239068812.4753.15.camel@localhost.localdomain>
Date:	Mon, 06 Apr 2009 21:46:52 -0400
From:	Steven Rostedt <srostedt@...hat.com>
To:	GeunSik Lim <leemgs1@...il.com>
Cc:	Ingo Molnar <mingo@...e.hu>,
	rt-users <linux-rt-users@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Nikanth Karthikensan <knikanth@...e.de>
Subject: Re: [PATCH] Update old Mini-HOWTO for ftrace


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 <leemgs1@...il.com>
>     Signed-off-by: Steven Rostedt <srostedt@...hat.com>
>     Signed-off-by: Ingo Molnar <mingo@...e.hu>
> ---
>  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


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/