On Wed, Nov 30, 2016 at 01:13:03PM -0600, Josh Poimboeuf wrote:
> This question was probably intended for other folks, but I should point
> out that idle tasks *do* invoke the scheduler. cpu_idle_loop() calls
> schedule_preempt_disabled().
Right, but that doesn't matter I think. The below will simply not call
rcu_note_voluntary_context_switch() from the idle task, which would be
fine I think.
> > So is the following a sensible approach, or should I look elsewhere?
> >
> > #define cond_resched_rcu_qs() \
> > do { \
> > if (!is_idle_task(current) && !cond_resched()) \
> > rcu_note_voluntary_context_switch(current); \
You should reverse your conditions though:
if (!cond_resched() && !is_idle_task(current))
rcu_note_voluntary_context_switch(current);
That way we'll still do cond_resched() and you only gate the RCU call.
