Re: [PATCH 2/4] tracing: add event trace infrastructure

[Ingo Molnar <mingo@elte.hu>]

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Wed, 2009-02-25 at 01:22 -0800, Andrew Morton wrote:
> 
> > Parse this:
> > 
> > irqsoff latency trace v1.1.5 on 2.6.26-rc8
> > --------------------------------------------------------------------
> >  latency: 97 us, #3/3, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2)
> >     -----------------
> >     | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0)
> >     -----------------
> >  => started at: apic_timer_interrupt
> >  => ended at:   do_softirq
> > 
> > #                _------=> CPU#
> > #               / _-----=> irqs-off
> > #              | / _----=> need-resched
> > #              || / _---=> hardirq/softirq
> > #              ||| / _--=> preempt-depth
> > #              |||| /
> > #              |||||     delay
> > #  cmd     pid ||||| time  |   caller
> > #     \   /    |||||   \   |   /
> >   <idle>-0     0d..1    0us+: trace_hardirqs_off_thunk (apic_timer_interrupt)
> >   <idle>-0     0d.s.   97us : __do_softirq (do_softirq)
> >   <idle>-0     0d.s1   98us : trace_hardirqs_on (do_softirq)
> > 
> > your time starts now.
> 
> awk '/^#/ { start=1; next } { if (!start) next; .... }'

yeah.

For /debug/tracing/trace the convention is that a simple:

  grep -v '^#'

pattern will filter out the header as "comments".

	Ingo