Re: [PATCH 7/7] tracing: add hierarchical enabling of events

[Frederic Weisbecker <fweisbec@gmail.com>]

On Wed, May 06, 2009 at 11:13:42PM -0400, Steven Rostedt wrote:
> From: Steven Rostedt <srostedt@redhat.com>
> 
> With the current event directory, you can only enable individual events.
> The file debugfs/tracing/set_event is used to be able to enable or
> disable several events at once. But that can still be awkward.
> 
> This patch adds hierarchical enabling of events. That is, each directory
> in debugfs/tracing/events has an "enable" file. This file can enable
> or disable all events within the directory and below.
> 
>  # echo 1 > /debugfs/tracing/events/enable
> 
> will enable all events.
> 
>  # echo 1 > /debugfs/tracing/events/sched/enable
> 
> will enable all events in the sched subsystem.
> 
>  # echo 1 > /debugfs/tracing/events/enable
>  # echo 0 > /debugfs/tracing/events/irq/enable
> 
> will enable all events, but then disable just the irq subsystem events.
> 
> When reading one of these enable files, there are four results:
> 
>  0 - all events this file affects are disabled
>  1 - all events this file affects are enabled
>  X - there is a mixture of events enabled and disabled
>  ? - this file does not affect any event



Nice, I also planned to support hierarchical events but I'm too
slow, thanks!