From a68a2bb28bbf7a6dd4672a25bd87fd1b5db4fa7d Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 3 May 2017 08:34:57 -0700 Subject: rcu: Move docbook comments out of rcupdate.h The include/linux/rcupdate.h file is included by more than 200 files, so shrinking it should provide some build-time benefits. This commit therefore moves several docbook comments from rcupdate.h to kernel/rcu/update.c, kernel/rcu/tree.c, and kernel/rcu/tree_plugin.h, thus reducing the number of times that the compiler has to scan these comments. This likely provides only a small benefit, but every little bit helps. This commit also fixes a malformed bulleted list noted by the 0day Test Robot. Reported-by: Ingo Molnar Signed-off-by: Paul E. McKenney --- kernel/rcu/update.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'kernel/rcu/update.c') diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 123a9c4b5055..84dec2c8ad1b 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -576,9 +576,23 @@ module_param(rcu_task_stall_timeout, int, 0644); static void rcu_spawn_tasks_kthread(void); static struct task_struct *rcu_tasks_kthread_ptr; -/* - * Post an RCU-tasks callback. First call must be from process context - * after the scheduler if fully operational. +/** + * call_rcu_tasks() - Queue an RCU for invocation task-based grace period + * @rhp: structure to be used for queueing the RCU updates. + * @func: actual callback function to be invoked after the grace period + * + * The callback function will be invoked some time after a full grace + * period elapses, in other words after all currently executing RCU + * read-side critical sections have completed. call_rcu_tasks() assumes + * that the read-side critical sections end at a voluntary context + * switch (not a preemption!), entry into idle, or transition to usermode + * execution. As such, there are no read-side primitives analogous to + * rcu_read_lock() and rcu_read_unlock() because this primitive is intended + * to determine that all tasks have passed through a safe state, not so + * much for data-strcuture synchronization. + * + * See the description of call_rcu() for more detailed information on + * memory ordering guarantees. */ void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func) { -- cgit v1.2.3