Re: [PATCH] rcu: Remove some superfluous lines

Paul E. McKenney
2016-03-10T13:42:12Z

On Thu, Mar 10, 2016 at 09:49:04AM +0100, Peter Zijlstra wrote:
>
> I think you'll find this condition is superfluous, as the whole function
> is under #ifdef of that same.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Right you are! It got moved under that #ifdef in the process of merging
the RCU, hotplug, and swait changes, and I failed to notice. Good catch!

I will apply this to my tree once -rc1 comes out, as it will apply to
-rcu at that point.

Or maybe we should remove the #ifdef and add IS_ENABLED() to the other
functions under that #ifdef. Thoughts?

Thanx, Paul

> ---
> kernel/rcu/tree.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 4f7369d54de0..dd2646e56456 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -4237,9 +4237,6 @@ static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
> struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
> struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
>
> - if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
> - return;
> -
> /* Remove outgoing CPU from mask in the leaf rcu_node structure. */
> mask = rdp->grpmask;
> raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
>