Re: [PATCH v5] tracing: Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast

[Sebastian Andrzej Siewior]

On 2026-01-09 13:58:21 [-0500], Mathieu Desnoyers wrote:
> On 2026-01-09 12:21, Steven Rostedt wrote:
> > > Using SRCU-fast to protect tracepoint callback iteration makes sense
> > > for preempt-rt, but I'd recommend moving the migrate disable guard
> > > within the bpf callback code rather than slowing down other tracers
> > > which execute within a short amount of time. Other tracers can then
> > > choose to disable preemption rather than migration if that's a better
> > > fit for their needs.
> > 
> > This is a discussion with the BPF folks.
> 
> FWIW, the approach I'm proposing would be similar to what I've done for
> faultable syscall tracepoints.

I just started reading this thread but we could limit the
migrate_disable() to only the BPF callback part so it does not effect
the whole tracepoint if there not a BFP program attached to it.

Sebastian