Re: [PATCH RFC] doc: rcu: remove obsolete (non-)requirement about disabling preemption

[Steven Rostedt]

On Thu, 18 Oct 2018 17:19:32 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxxxxx> wrote:

> I figured that whoever calls preempt_enable_no_resched() is taking the
> responsibility for permitting preemption in the near future, and if they
> fail to do so, they will get called on it.  Hard to hide from the latency
> tracer, after all.  ;-)

Correct, and doing a search of preempt_enable_no_resched() I see
there's one in the ftrace ring buffer code, that was added a long time
ago (2008) to fix a recursion bug that no longer exists, and this now
can leak a preemption point.

I'll have to go fix that :-(

-- Steve