From 5a0465e17a18c467b712a816985b7b8dd8d10c16 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 4 May 2017 11:31:04 -0700 Subject: srcu: Shrink srcu.h by moving docbook and private function The call_srcu() docbook entry is currently in include/linux/srcu.h, which causes needless processing for each include point. This commit therefore moves this entry to kernel/rcu/srcutree.c, which the compiler reads only once. In addition, the srcu_batches_completed() function is used only within RCU and its torture-test suites. This commit therefore also moves this function's declaration from include/linux/srcutiny.h, include/linux/srcutree.h, and include/linux/srcuclassic.h to kernel/rcu/rcu.h. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcu.h | 6 ++++++ kernel/rcu/srcutree.c | 17 +++++++++++++++++ 2 files changed, 23 insertions(+) (limited to 'kernel/rcu') diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 5b76a5b..74d9fc2 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -492,6 +492,11 @@ static inline unsigned long rcu_exp_batches_completed_sched(void) return 0; } +static inline unsigned long srcu_batches_completed(struct srcu_struct *sp) +{ + return 0; +} + static inline void rcu_force_quiescent_state(void) { } @@ -519,6 +524,7 @@ unsigned long rcu_batches_completed_bh(void); unsigned long rcu_batches_completed_sched(void); unsigned long rcu_exp_batches_completed(void); unsigned long rcu_exp_batches_completed_sched(void); +unsigned long srcu_batches_completed(struct srcu_struct *sp); void show_rcu_gp_kthreads(void); void rcu_force_quiescent_state(void); void rcu_bh_force_quiescent_state(void); diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index cc06dbf..66a998f 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -854,6 +854,23 @@ void __call_srcu(struct srcu_struct *sp, struct rcu_head *rhp, srcu_funnel_exp_start(sp, sdp->mynode, s); } +/** + * call_srcu() - Queue a callback for invocation after an SRCU grace period + * @sp: srcu_struct in queue the callback + * @head: structure to be used for queueing the SRCU callback. + * @func: function to be invoked after the SRCU grace period + * + * The callback function will be invoked some time after a full SRCU + * grace period elapses, in other words after all pre-existing SRCU + * read-side critical sections have completed. However, the callback + * function might well execute concurrently with other SRCU read-side + * critical sections that started after call_srcu() was invoked. SRCU + * read-side critical sections are delimited by srcu_read_lock() and + * srcu_read_unlock(), and may be nested. + * + * The callback will be invoked from process context, but must nevertheless + * be fast and must not block. + */ void call_srcu(struct srcu_struct *sp, struct rcu_head *rhp, rcu_callback_t func) { -- cgit v1.1