linux-kernel - Re: Nested events with zero deltas, can use absolute timestamps instead?

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Message-ID: <20190524112457.58b24d89@gandalf.local.home>
Date:   Fri, 24 May 2019 11:24:57 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Jason Behmer <jbehmer@...gle.com>
Cc:     tom.zanussi@...ux.intel.com, linux-kernel@...r.kernel.org
Subject: Re: Nested events with zero deltas, can use absolute timestamps
 instead?

On Fri, 24 May 2019 08:11:12 -0700
Jason Behmer <jbehmer@...gle.com> wrote:

> > > What do you think of that?  
> >
> > I don't think that's confusing if its well documented. Have the user
> > flag called "force_absolute_timestamps", that way it's not something
> > that the user will think that we wont have absolute timestamps if it is
> > zero. Have the documentation say:
> >
> >  Various utilities within the tracing system require that the ring
> >  buffer uses absolute timestamps. But you may force the ring buffer to
> >  always use it, which will give you unique timings with nested tracing
> >  at the cost of more usage in the ring buffer.
> >
> > -- Steve  
> 
> Ah, I was thinking of doing this within the existing timestamp_mode
> config file.  Having a separate file does make it much less confusing.

Not a separate file, but a new tracing option.

-- Steve