Re: Ftrace: can trace kthread?

Peter Zijlstra
2010-10-21T10:12:21Z

On Thu, 2010-10-21 at 16:59 +0800, Figo.zhang wrote:
> > I just
> > echo 0 > tracing_enabled
> > echo function > current_tracer
> > echo 374(pid of flush) > set_ftrace_pid
> > echo 1 > tracing_enabled
> > wait some time
> > echo 0 > tracing_enabled
> > cat trace
> >
> > So I think this answer your question "could kthread be traced?"
>
> i do it the same of you.

> but i canot trace nothing.

Your initial attempt had:

echo kswapd > /sys/kernel/debug/tracing/set_graph_function

have you reset that state?