Messages in this thread | | | Subject | Re: Ftrace: can trace kthread? | From | Steven Rostedt <> | Date | Thu, 21 Oct 2010 09:31:41 -0400 |
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On Thu, 2010-10-21 at 12:12 +0200, Peter Zijlstra wrote: > On Thu, 2010-10-21 at 16:59 +0800, Figo.zhang wrote: > > > I just > > > echo 0 > tracing_enabled
I need to remove that file. "tracing_enabled" is pretty much deprecated, just use tracing_on to enable and disable the trace recording.
> > > 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
Yeah, that wont work. That's because kswapd() is called at system startup and goes into a loop. The function graph tracer will never see that function again (it's not called again). It can't know what function it is in, only what functions it enters.
-- Steve
> > have you reset that state?
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