Messages in this thread | | | Date | Wed, 3 Dec 2008 09:19:06 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 2/2] tracing/function-graph-tracer: improve duration output |
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* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> Frederic Weisbecker wrote: > > Impact: better output of duration for long calls > > > > The old duration output didn't exceeded 9999.999 us to fit the column > > and the nanosecs were always 3 numbers. As Ingo suggested, it's better > > to have the whole microseconds elapsed time and shift the nanosecs precision > > if needed to fit the maximum 7 numbers. And usec need more number, the case > > should be rare and important enough to break a bit the column alignment to > > show it. > > > > So, depending of the duration value, we now have these patterns: > > > > u.nnn > > uu.nnn > > uuu.nnn > > uuuu.nnn > > uuuuu.nn > > uuuuuu.n > > uuuuuuuu.....
applied, thanks!
> 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:
> 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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