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/init_task.h | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 6df7f9fe0d01..2bb4c4f3531a 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -102,12 +102,6 @@ extern struct group_info init_groups; #define INIT_IDS #endif -#ifdef CONFIG_RCU_BOOST -#define INIT_TASK_RCU_BOOST() \ - .rcu_boost_mutex = NULL, -#else -#define INIT_TASK_RCU_BOOST() -#endif #ifdef CONFIG_TREE_PREEMPT_RCU #define INIT_TASK_RCU_TREE_PREEMPT() \ .rcu_blocked_node = NULL, @@ -119,8 +113,7 @@ extern struct group_info init_groups; .rcu_read_lock_nesting = 0, \ .rcu_read_unlock_special = 0, \ .rcu_node_entry = LIST_HEAD_INIT(tsk.rcu_node_entry), \ - INIT_TASK_RCU_TREE_PREEMPT() \ - INIT_TASK_RCU_BOOST() + INIT_TASK_RCU_TREE_PREEMPT() #else #define INIT_TASK_RCU_PREEMPT(tsk) #endif -- cgit v1.2.3