Re: [RFC][PATCH] ftrace interface for blktrace

From: Arnaldo Carvalho de Melo
Date: Fri Jan 16 2009 - 14:42:26 EST


Em Fri, Jan 16, 2009 at 02:15:55PM -0500, Steven Rostedt escreveu:
>
> Arnaldo,
>
> Cool stuff!
>
> On Fri, 16 Jan 2009, Arnaldo Carvalho de Melo wrote:
>
> > Hi Jens,
> >
> > The patch below adds a ftrace interface for blktrace, allowing
> > people to use it without any required userspace tools, using sysfs to setup the
> > act_mask, pid, start_lba, end_lba.
> >
> > Example usage:
> >
> > [root@f10-1 ~]# mount -t debugfs none /sys/kernel/debug/
>
> I think you are the only person that mounts debugfs on the "official"
> location ;-)
>
> > [root@f10-1 ~]# ls /sys/block/sda/sda1/trace/
> > act_mask enable end_lba pid start_lba
> > [root@f10-1 ~]# cat /sys/kernel/debug/tracing/available_tracers
> > blk function_graph wakeup function sched_switch nop
> > [root@f10-1 ~]# echo blk > /sys/kernel/debug/tracing/current_tracer
>
> You must like to type.

Nah, autocompletion and 'set -o vi' command line editing makes it easy,
but yes, one could mount it as:

# mkdir /d
# mount -t debugfs none /d

:-)

Other than that, I guess the implementation must be OK, huh? :-)

Well, off to play fat boys soccer.

- Arnaldo
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