Re: [PATCH 2/2] tracing/function-graph-tracer: improve durationoutput

[Steven Rostedt]

On Wed, 3 Dec 2008, Ingo Molnar wrote:
> 
> > An example of a trace after these two patches (with funcgraph-proc enabled):
> > 
> >  0)    cat-2796    |               |            put_prev_task_fair() {
> >  0)    cat-2796    |   0.609 us    |              update_curr();
> >  0)    cat-2796    |   1.842 us    |            }
> >  0)    cat-2796    |               |            pick_next_task_fair() {
> >  0)    cat-2796    |   0.526 us    |              wakeup_preempt_entity();
> >  0)    cat-2796    |   0.797 us    |              set_next_entity();
> >  0)    cat-2796    |   0.541 us    |              hrtick_start_fair();
> >  0)    cat-2796    |   4.195 us    |            }
> >  0)    cat-2796    |   1.263 us    |            _spin_trylock();
> >  0)    cat-2796    |   0.624 us    |            _spin_unlock();
> >  0)    cat-2796    |   0.789 us    |            _spin_trylock();
> >  0)    cat-2796    |   0.617 us    |            _spin_unlock();
> >  0)    cat-2796    |   0.579 us    |            native_load_sp0();
> >  0)    cat-2796    |   0.722 us    |            native_load_tls();
> >
> >  ------------------------------------------
> >  | 0)    cat-2796    =>   events/-9   
> >  ------------------------------------------
> 
> small detail: i'd suggest to remove the newline before the context-switch 
> box. That makes it appear visually to attach logically with the 
> switch-out place, not the switch-in place:

Actually, I was also thinking of keeping the CPU number in front:

 ------------------------------------------
 0)    cat-2796    =>   events/-9
 ------------------------------------------

This way we can easily grep for a common CPU and still get the context 
switches:

grep '^0)' trace > /tmp/trace0

Of course it will probably also work without the '^' now, but then it 
might grab ftrace_printks with a '0)' if we add those.

-- Steve

> 
> >  0)    cat-2796    |   0.579 us    |            native_load_sp0();
> >  0)    cat-2796    |   0.722 us    |            native_load_tls();
> >  ------------------------------------------
> >  | 0)    cat-2796    =>   events/-9   
> >  ------------------------------------------
> > 
> >  0)   events/-9    |               |    finish_task_switch() {
> >  0)   events/-9    |   0.789 us    |      _spin_unlock_irq();
> >  0)   events/-9    |   2.309 us    |    }
> >  0)   events/-9    | ! 269848.5 us |  }
> 
> which is what we want to express.
> 
> 	Ingo
> 
> 
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