Messages in this thread | | | Date | Thu, 6 Nov 2008 09:46:57 -0500 (EST) | From | Steven Rostedt <> | Subject | Re: sys_sched_yield keeps locked irq before call of schedule() |
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On Thu, 6 Nov 2008, Ingo Molnar wrote: > > > > Quick note. Currently ftrace_printk only shows up if it is set in the > > iter_ctrl. > > > > echo trace_printk > /debug/tracing/iter_ctrl > > > > I'll send out a patch to have it on by default. > > ok, agreed - but in that case please make the NOP tracer > tracing_enabled=0 by default. (we'll get a lot of ftrace_printk > tracepoints by default otherwise)
Hmm, I think it may be good to leave it on even for the nop tracer.
ftrace_printk's should not be out in open code unless someone is actually debugging it. You can use ftrace_printk inside a tracer to write stuff, but that printk should be protected somehow by the encompassing tracer.
i.e.
some_tracer(void) { if (!tracer_enabled) return; ftrace_printk("my special stuff\n"); }
I would think if someone is debugging their code by using ftrace_printk, they probably want it to show up right away, without having to remember to do a...
echo trace_printk > /debug/tracing/iter_ctrl
And still have it show up in the nop tracer.
-- Steve
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