Re: [PATCH v5 tip/core/rcu 15/16] rcu: Make RCU-tasks wait for idle tasks

[Steven Rostedt]

On Wed, 13 Aug 2014 16:07:05 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Wed, Aug 13, 2014 at 09:51:32AM -0400, Steven Rostedt wrote:
> 
> > I still need to look at the patches, but if this is just for the idle
> > case, then we don't need it. The idle case can be solved with a simple
> > sched_on_each_cpu(). I need a way to solve waiting for processes to
> > finish from a preemption point.
> > 
> > That's all I want, and if we can remove the "idle" case and document it
> > well that it's not covered and a sched_on_each_cpu() may be needed,
> > then I'm fine with that.
> > 
> > 	sched_on_each_cpu(dummy_op);
> > 	call_rcu_tasks(free_tramp);
> 
> Sure, but why not dtrt and push rcu_idle hooks all the way down into the
> idle drivers if and where appropriate?
> 
> There isn't _that_ much idle driver code. Also, some stuff should be
> cleaned up; we're already calling stop_critical_timings() in the generic
> idle code, and then calling it again in the cpuidle drivers.
> 
> 

True, perhaps the rcu code should hook into the stop_critical_timings
code?

-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/