From abaa93d9e1de2c29297e69ddba8ddd38f15064cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 12 Jun 2014 13:30:25 -0700 Subject: rcu: Simplify priority boosting by putting rt_mutex in rcu_node RCU priority boosting currently checks for boosting via a pointer in task_struct. However, this is not needed: As Oleg noted, if the rt_mutex is placed in the rcu_node instead of on the booster's stack, the boostee can simply check it see if it owns the lock. This commit makes this change, shrinking task_struct by one pointer and the kernel by thirteen lines. Suggested-by: Oleg Nesterov Signed-off-by: Paul E. McKenney --- include/linux/sched.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/sched.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index 306f4f0c987a..3cfbc05e66e6 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1270,9 +1270,6 @@ struct task_struct { #ifdef CONFIG_TREE_PREEMPT_RCU struct rcu_node *rcu_blocked_node; #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ -#ifdef CONFIG_RCU_BOOST - struct rt_mutex *rcu_boost_mutex; -#endif /* #ifdef CONFIG_RCU_BOOST */ #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) struct sched_info sched_info; @@ -2009,9 +2006,6 @@ static inline void rcu_copy_process(struct task_struct *p) #ifdef CONFIG_TREE_PREEMPT_RCU p->rcu_blocked_node = NULL; #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ -#ifdef CONFIG_RCU_BOOST - p->rcu_boost_mutex = NULL; -#endif /* #ifdef CONFIG_RCU_BOOST */ INIT_LIST_HEAD(&p->rcu_node_entry); } -- cgit v1.2.3