[PATCH tip/core/rcu 07/20] rcu: Remove obsolete boost statistics for debugfs

From: Paul E. McKenney
Date: Mon Feb 26 2018 - 16:57:41 EST


The debugfs interface displayed statistics on RCU priority boosting,
but this interface has since been removed. This commit therefore
removes the no-longer-used rcu_data structure's ->n_tasks_boosted,
->n_exp_boosts, and ->n_exp_boosts and their updates.

If this information proves necessary in the future, the corresponding
event traces will be added.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.h | 6 ------
kernel/rcu/tree_plugin.h | 8 ++------
2 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 6488a3b0e729..01abd1c4e5da 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -146,12 +146,6 @@ struct rcu_node {
/* boosting for this rcu_node structure. */
unsigned int boost_kthread_status;
/* State of boost_kthread_task for tracing. */
- unsigned long n_tasks_boosted;
- /* Total number of tasks boosted. */
- unsigned long n_exp_boosts;
- /* Number of tasks boosted for expedited GP. */
- unsigned long n_normal_boosts;
- /* Number of tasks boosted for normal GP. */
#ifdef CONFIG_RCU_NOCB_CPU
struct swait_queue_head nocb_gp_wq[2];
/* Place for rcu_nocb_kthread() to wait GP. */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7e31fb1e9fd8..0d552985b905 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -963,14 +963,10 @@ static int rcu_boost(struct rcu_node *rnp)
* expedited grace period must boost all blocked tasks, including
* those blocking the pre-existing normal grace period.
*/
- if (rnp->exp_tasks != NULL) {
+ if (rnp->exp_tasks != NULL)
tb = rnp->exp_tasks;
- rnp->n_exp_boosts++;
- } else {
+ else
tb = rnp->boost_tasks;
- rnp->n_normal_boosts++;
- }
- rnp->n_tasks_boosted++;

/*
* We boost task t by manufacturing an rt_mutex that appears to
--
2.5.2