Re: [PATCH] tracing, rcu: Remove no longer used trace event rcu_prep_idle

From: Steven Rostedt
Date: Thu Oct 12 2017 - 18:32:45 EST


On Thu, 12 Oct 2017 15:26:45 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:

> On Thu, Oct 12, 2017 at 06:12:57PM -0400, Steven Rostedt wrote:
> > From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> >
> > Commit c0f4dfd4f90 ("rcu: Make RCU_FAST_NO_HZ take advantage of
> > numbered callbacks") removed the only instances of trace_rcu_prep_idle,
> > but did not remove the TRACE_EVENT() that creates it. As defined trace
> > events take up memory within the kernel even when they are not used,
> > this is a waste of space. Remove the obsolete event.
> >
> > Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
>
> Good catch, queued for review and testing, thank you!
>
> Slight change in the context of the final hunk of the patch for -rcu,
> updated version shown below.

I now have a utility that complains when tracepoints are not used. But
I'm working on getting this to work at build time and not run time. In
the mean time, I might as well do some clean up ;-)

-- Steve