On Thu, Feb 25, 2016 at 04:34:23PM -0800, Steve Muckle wrote: > >> + /* > >> + * Ensure that all CPUs currently part of this policy are out > >> + * of the hot path so that if this policy exits we can free gd. > >> + */ > >> + preempt_disable(); > >> + smp_call_function_many(policy->cpus, dummy, NULL, true); > >> + preempt_enable(); > > > > I'm not sure how this works, can you please tell me? > > Peter correctly interpreted my intentions. > > The RCU possibility also crossed my mind. They both seemed like a bit of > a hack to me - this wouldn't really be doing any RCU per se, rather > relying on its implementation. I'll switch to RCU since that seems to be > preferred though. It's certainly cleaner to write.
RCU is widely used in this fashion. synchronize_sched() is explicitly constructed to sync against preempt disable sections. This is not an implementation detail.
