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SubjectRe: [PATCH] tracing: branch tracer, tweak output

* Ingo Molnar <mingo@elte.hu> wrote:

> a small detail:
>
> > For example:
> >
> > bash-3471 [003] 357.014755: [INCORRECT] sched_info_dequeued:sched_stats.h:177
> > bash-3471 [003] 357.014756: [correct] update_curr:sched_fair.c:489
> > bash-3471 [003] 357.014758: [correct] calc_delta_fair:sched_fair.c:411
> > bash-3471 [003] 357.014759: [correct] account_group_exec_runtime:sched_stats.h:356
> > bash-3471 [003] 357.014761: [correct] update_curr:sched_fair.c:489
> > bash-3471 [003] 357.014763: [INCORRECT] calc_delta_fair:sched_fair.c:411
> > bash-3471 [003] 357.014765: [correct] calc_delta_mine:sched.c:1279
>
> it's always good to have such fields aligned vertically. Something
> like this would be shorter and visually much easier to parse:
>
> bash-3471 [003] 357.014755: [ MISS ] sched_info_dequeued:sched_stats.h:177
> bash-3471 [003] 357.014756: [ .... ] update_curr:sched_fair.c:489
> bash-3471 [003] 357.014758: [ .... ] calc_delta_fair:sched_fair.c:411
>
> any objections against the patch below which implements this?

and note that this is really a "branch tracer/profiler", with branch
taken/untaken prediction hits/misses. The likely()/unlikely() is an
in-kernel tool to manually predict branch likelyhood - and for now we
trace and profile those points that we tweaked manually - but there's
no reason why that should be true for future versions too.

So i think it's generally better to think of these events as hit/miss
events.

Ingo


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