On Tue, Nov 15, 2016 at 01:53:22PM +0530, Viresh Kumar wrote: > @@ -308,7 +313,21 @@ static void sugov_irq_work(struct irq_work *irq_work) > struct sugov_policy *sg_policy; > > sg_policy = container_of(irq_work, struct sugov_policy, irq_work); > + > + /* > + * For Real Time and Deadline tasks, schedutil governor shoots the > + * frequency to maximum. And special care must be taken to ensure that > + * this kthread doesn't result in that. > + * > + * This is (mostly) guaranteed by the work_in_progress flag. The flag is > + * updated only at the end of the sugov_work() and before that schedutil > + * rejects all other frequency scaling requests. > + * > + * Though there is a very rare case where the RT thread yields right > + * after the work_in_progress flag is cleared. The effects of that are > + * neglected for now. > + */ > + kthread_queue_work(&sg_policy->worker, &sg_policy->work); > }
Right, so that's a wee bit icky, but its also entirely pre-existing code. Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org>
