request to add trace off and trace on with events

[Steven Rostedt <rostedt@goodmis.org>]

Hi Tom,

Could you add a way to do a call to tracing_on() or tracing_off() via
the filters. I would like to do something like:


echo 'if (pid == 1234) traceoff' > events/sched/sched_wakeup/filter

Where, if the sched_wakeup event is hit with pid == 1234 it will turn
tracing off.

I would also like to do just:

echo 'traceoff' > events/sched/sched_wakeup/filter

to disable tracing every time the event is hit.

Perhaps you can just add a call back where the kernel could register
something to be called if a command is used in the filter.

register_event_command("traceoff", trace_off_cb);

where the trace_off_cb is a function that is called by the event if the
traceoff command is hit. This would allow other commands to be added
later.

Would something like this be doable, I was looking at the code, and it
certain looks feasible, but it would take me longer to implement it than
it would you :-)

Thanks,

-- Steve