Re: [PATCH] rcu: Remove unused rcu_state.boost

From: Paul E. McKenney
Date: Mon Dec 13 2021 - 14:42:02 EST


On Mon, Dec 13, 2021 at 12:32:09PM +0530, Neeraj Upadhyay wrote:
> Signed-off-by: Neeraj Upadhyay <quic_neeraju@xxxxxxxxxxx>

Good eyes! This has since been replaced by the ->can_boost field of
the rcu_torture_ops structure.

Queued for review and testing, thank you!

Thanx, Paul

> ---
> kernel/rcu/tree.h | 5 ++---
> kernel/rcu/tree_plugin.h | 2 --
> 2 files changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> index 4b889081f4f4..caea946700f3 100644
> --- a/kernel/rcu/tree.h
> +++ b/kernel/rcu/tree.h
> @@ -303,9 +303,8 @@ struct rcu_state {
>
> /* The following fields are guarded by the root rcu_node's lock. */
>
> - u8 boost ____cacheline_internodealigned_in_smp;
> - /* Subject to priority boost. */
> - unsigned long gp_seq; /* Grace-period sequence #. */
> + unsigned long gp_seq ____cacheline_internodealigned_in_smp;
> + /* Grace-period sequence #. */
> unsigned long gp_max; /* Maximum GP duration in */
> /* jiffies. */
> struct task_struct *gp_kthread; /* Task for grace periods. */
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index 1439cb3680eb..54ef0e8c8742 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -1174,8 +1174,6 @@ static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp)
> if (rnp->boost_kthread_task || !rcu_scheduler_fully_active)
> goto out;
>
> - rcu_state.boost = 1;
> -
> t = kthread_create(rcu_boost_kthread, (void *)rnp,
> "rcub/%d", rnp_index);
> if (WARN_ON_ONCE(IS_ERR(t)))
> --
> 2.17.1
>