Re: [PATCH v4 1/5] tracing: Introduce faultable tracepoints

[Mathieu Desnoyers]

On 2023-11-21 11:07, Steven Rostedt wrote:
> On Tue, 21 Nov 2023 11:00:13 -0500
> Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>
> > > tasks-tracing-rcu:
> > >     extention of tasks to have critical-sections ? Should this simply be
> > >     tasks?
> >
> > tasks-trace-rcu is meant to allow tasks to block/take a page fault
> > within the read-side. It is specialized for tracing and has a single
> > domain. It does not need the smp_mb on the read-side, which makes it
> > lower-overhead than SRCU.
>
> IOW, task-trace-rcu allows the call to schedule in its critical section,
> whereas task-rcu does not?

Correct.

And unlike preemptible rcu, tasks-trace-rcu allows calls to schedule 
which do not provide priority inheritance guarantees (such as I/O 
triggered by page faults).

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com