Re: Adding latency tracking to trace-cmd

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 24 Feb 2021 19:22:48 +0000
<Viktor.Rosendahl@bmw.de> wrote:
> > 
> > My question to you is, would you like to work on adding that feature to
> > trace-cmd?  
> 
> I would be interested to work on the feature but I would probably need
> permission from my employer, also in case I do it as a spare time project.
> 
> For this reason, I will need some time come to a decision. I will get back to
> you when I know the answer.

Hi Viktor,

Any word on if your employer would let you work on trace-cmd?

> 
> > 
> >   git://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git
> > 
> > (which requires the libtracefs and libtracevent libraries).
> > 
> > I'm thinking if someone were to do:
> > 
> >  trace-cmd record -p wakeup_rt 
> > 
> > It would then act just like the latency-collector and record every new
> > instance of a latency into the trace.dat file, where:
> > 
> >  trace-cmd report
> > 
> > would then nicely format that data for the user.
> > 
> > Thoughts?  
> 
> It seems like trace-cmd is mostly GPL-2.0. The latency-collector is also GPL-
> 2.0, so I guess that it would be possible to take snippets of code and
> inspiration from it.
> 
> Would you allow the hackish random algorithm to be used in trace-cmd?
> I mean the "--random" option in latency-collector.
> 

If you feel it is useful, sure. Although a definition of what it exactly
does needs to be a bit more explained. I'm not really sure what use the
--random option is for the latency tracer.

-- Steve