Re: [PATCH 3/7] rcu: fix header guard for rcu_all_qs()

[Peter Zijlstra]

On Thu, Oct 10, 2024 at 08:41:23AM +0200, Sebastian Andrzej Siewior wrote:
> On 2024-10-09 09:54:07 [-0700], Ankur Arora wrote:
> > rcu_all_qs() is defined for !CONFIG_PREEMPT_RCU but the declaration
> > is conditioned on CONFIG_PREEMPTION.
> > 
> > With CONFIG_PREEMPT_LAZY, CONFIG_PREEMPTION=y does not imply
> > CONFIG_PREEMPT_RCU=y.
> 
> From kernel/rcu/Kconfig:
> | config PREEMPT_RCU
> |         bool
> |         default y if PREEMPTION
> 
> this looks like PREEMPT_RCU implies PREEMPTION.

The point was to make PREEMPT_RCU=n possible even when PREEMPTION=y,
which is fine.