From 3fbd7ee285b2bbc6eebd15a3c8786d9776a402a8 Mon Sep 17 00:00:00 2001 From: Eric W. Biederman Date: Sat, 14 Sep 2019 07:33:34 -0500 Subject: tasks: Add a count of task RCU users Add a count of the number of RCU users (currently 1) of the task struct so that we can later add the scheduler case and get rid of the very subtle task_rcu_dereference(), and just use rcu_dereference(). As suggested by Oleg have the count overlap rcu_head so that no additional space in task_struct is required. Inspired-by: Linus Torvalds Inspired-by: Oleg Nesterov Signed-off-by: Eric W. Biederman Signed-off-by: Peter Zijlstra (Intel) Cc: Chris Metcalf Cc: Christoph Lameter Cc: Davidlohr Bueso Cc: Kirill Tkhai Cc: Linus Torvalds Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Russell King - ARM Linux admin Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/87woebdplt.fsf_-_@x220.int.ebiederm.org Signed-off-by: Ingo Molnar --- include/linux/sched/task.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sched') diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 3d90ed8f75f0..153a683646ac 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -120,6 +120,7 @@ static inline void put_task_struct(struct task_struct *t) } struct task_struct *task_rcu_dereference(struct task_struct **ptask); +void put_task_struct_rcu_user(struct task_struct *task); #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT extern int arch_task_struct_size __read_mostly; -- cgit v1.2.3