Re: [PATCH v3 07/13] rv: Convert the opid monitor to a hybrid automaton

Nam Cao
2025-12-18T06:50:11Z

Gabriele Monaco <gmonaco@redhat.com> writes:
> The opid monitor validates that wakeup and need_resched events only
> occur with interrupts and preemption disabled by following the
> preemptirq tracepoints.
> As reported in [1], those tracepoints might be inaccurate in some
> situations (e.g. NMIs).
>
> Since the monitor doesn't validate other ordering properties, remove the
> dependency on preemptirq tracepoints and convert the monitor to a hybrid
> automaton to validate the constraint during event handling.
> This makes the monitor more robust by also removing the workaround for
> interrupts missing the preemption tracepoints, which was working on
> PREEMPT_RT only and allows the monitor to be built on kernels without
> the preemptirqs tracepoints.
>
> [1] - https://lore.kernel.org/lkml/20250625120823.60600-1-gmonaco@redhat.com
>
> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>

Reviewed-by: Nam Cao <namcao@linutronix.de>