Re: [PATCH 0/2] sparc64: Use low latency path to resume idle cpu

From: David Miller
Date: Thu Jul 20 2017 - 23:45:23 EST


From: Vijay Kumar <vijay.ac.kumar@xxxxxxxxxx>
Date: Thu, 20 Jul 2017 22:36:42 -0500

> I can give a try :). But looks to me one thing that will go wrong is
> irq accounting done in __irq_enter() and rcu_irq_enter().

Actually, the bigger problem is that scheduler_ipi() can raise a
software interrupt, and nothing will invoke it.

It's turning quite ugly to avoid the IRQ overhead, I must admit.
So ignore this for now.

In the longer term a probably cleaner way to do this is to have
a special direct version of scheduler_ipi() that invokes all the
necessary work, even the rebalance softirq, directly rather than
indirectly.