Re: [RFC][PATCH v2 08/11] context_tracking,rcu: Replace RCU dynticks counter with context_tracking

From: Peter Zijlstra
Date: Wed Sep 29 2021 - 15:18:37 EST


On Wed, Sep 29, 2021 at 11:37:01AM -0700, Paul E. McKenney wrote:

> And what happens to all of this in !CONFIG_CONTEXT_TRACKING kernels?
> Of course, RCU needs it unconditionally. (There appear to be at least
> parts of it that are unconditionally available, but I figured that I
> should ask. Especially given the !CONFIG_CONTEXT_TRACKING definition
> of the __context_tracking_cpu_seq() function.)

For !CONFIG_CONTEXT_TRACKING it goes *poof*.

Since the thing was called dynticks, I presumed it was actually dynticks
only, silly me (also, I didn't see any obvious !context_tracking usage
of it, i'll go audit it more carefully.