Re: [PATCH RFC] tracepoint: Introduce tracepoint callbacks executing with preempt on

From: Paul E. McKenney
Date: Fri Apr 27 2018 - 11:37:22 EST

On Fri, Apr 27, 2018 at 10:47:47AM -0400, Steven Rostedt wrote:
> On Fri, 27 Apr 2018 10:26:29 -0400 (EDT)
> Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
> > The general approach and the implementation look fine, except for
> > one small detail: I would be tempted to explicitly disable preemption
> > around the call to the tracepoint callback for the rcuidle variant,
> > unless we plan to audit every tracer right away to remove any assumption
> > that preemption is disabled in the callback implementation.
> I'm thinking that we do that audit. There shouldn't be many instances
> of it. I like the idea that a tracepoint callback gets called with
> preemption enabled.

Are you really sure you want to increase your state space that much?

Thanx, Paul