Re: WARNING in tracepoint_probe_register_prio (2)

From: Peter Zijlstra
Date: Thu Mar 15 2018 - 04:31:54 EST


On Wed, Mar 14, 2018 at 05:37:46PM -0400, Steven Rostedt wrote:
> On Tue, 13 Mar 2018 11:29:51 -0400 (EDT)
> Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>
> > Here is a WARN_ON() splat in tracepoint.c, which I suspect is caused
> > by perf trying to register the same probe twice to the tracepoint API.
> > We got another splat on unregister too, which I will forward in a
> > separate email.
> >
> > Thoughts ?
>
> Yes, it looks like it's perf not accounting for registered events
> properly.
>
> Peter?

I've not yet managed to reproduce, but if you look at the provided
repro.c file, you'll see it opens two _different_ events.