From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: timing information with perf
Date: Mon, 16 Nov 2015 22:31:44 -0300
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To: "Frank Ch. Eigler" <fche@redhat.com>
Cc: "Kornievskaia, Olga" <Olga.Kornievskaia@netapp.com>, linux-perf-users@vger.kernel.org

Em Mon, Nov 16, 2015 at 07:30:20PM -0500, Frank Ch. Eigler escreveu:
> acme wrote:
 
> > [...]
> > > For completeness, a complete systemtap implementation of this could look like:
> >  
> > > # stap -e '
> > >    global s, t%
> > >    probe kernel.trace("foobar_enter") {
> > >        t[tid()]=gettimeofday_us() 
> > >    } [...]
> > > '

> > Is that done syncronously?

> Meaning - calculated live as the tracepoints hit?  Yes, right during
> the respective callbacks.  No trace files nor postprocessing.

Right, 'perf trace' is in between those extremes, i.e. no synchronous
processing, no trace file for postprocessing. Just the ring buffer, that
is continuously processed.

- Arnaldo