Re: [RFC v1 2/2] rcu/tree: Remove dynticks_nmi_nesting counter

From: Paul E. McKenney
Date: Thu Aug 29 2019 - 12:10:23 EST

On Thu, Aug 29, 2019 at 10:43:55AM -0400, Joel Fernandes wrote:

[ . . . ]

> Paul, do we also nuke rcu_eqs_special_set()? Currently I don't see anyone
> using it. And also remove the bottom most bit of dynticks?
> Also what happens if a TLB flush broadcast is needed? Do we IPI nohz or idle
> CPUs are the moment?
> All of this was introduced in:
> b8c17e6664c4 ("rcu: Maintain special bits at bottom of ->dynticks counter")

Adding Andy Lutomirski on CC.

Andy, is this going to be used in the near term, or should we just get
rid of it?

Thanx, Paul