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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-07-31 13:34:32 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-09-20 21:16:18 -0700
commit7922cd0e562cb2b8da2c8a0afda2e1c9bb4a94e2 (patch)
treedce739485e55be9238c53bf70530a0b5e5a34aa3 /kernel/rcu/tree_plugin.h
parentf4ecea309d3e17ba5e90082308125ad23bd5701b (diff)
downloadlinux-sh-7922cd0e562cb2b8da2c8a0afda2e1c9bb4a94e2.tar.gz
rcu: Move rcu_report_exp_rnp() to allow consolidation
This is a nearly pure code-movement commit, moving rcu_report_exp_rnp(), sync_rcu_preempt_exp_done(), and rcu_preempted_readers_exp() so that later commits can make synchronize_sched_expedited() use them. The non-code-movement portion of this commit tags rcu_report_exp_rnp() as __maybe_unused to avoid build errors when CONFIG_PREEMPT=n. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
-rw-r--r--kernel/rcu/tree_plugin.h66
1 files changed, 0 insertions, 66 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 72df006de798..e73be8539978 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -536,72 +536,6 @@ void synchronize_rcu(void)
EXPORT_SYMBOL_GPL(synchronize_rcu);
/*
- * Return non-zero if there are any tasks in RCU read-side critical
- * sections blocking the current preemptible-RCU expedited grace period.
- * If there is no preemptible-RCU expedited grace period currently in
- * progress, returns zero unconditionally.
- */
-static int rcu_preempted_readers_exp(struct rcu_node *rnp)
-{
- return rnp->exp_tasks != NULL;
-}
-
-/*
- * return non-zero if there is no RCU expedited grace period in progress
- * for the specified rcu_node structure, in other words, if all CPUs and
- * tasks covered by the specified rcu_node structure have done their bit
- * for the current expedited grace period. Works only for preemptible
- * RCU -- other RCU implementation use other means.
- *
- * Caller must hold the root rcu_node's exp_funnel_mutex.
- */
-static int sync_rcu_preempt_exp_done(struct rcu_node *rnp)
-{
- return !rcu_preempted_readers_exp(rnp) &&
- READ_ONCE(rnp->expmask) == 0;
-}
-
-/*
- * Report the exit from RCU read-side critical section for the last task
- * that queued itself during or before the current expedited preemptible-RCU
- * grace period. This event is reported either to the rcu_node structure on
- * which the task was queued or to one of that rcu_node structure's ancestors,
- * recursively up the tree. (Calm down, calm down, we do the recursion
- * iteratively!)
- *
- * Caller must hold the root rcu_node's exp_funnel_mutex.
- */
-static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
- bool wake)
-{
- unsigned long flags;
- unsigned long mask;
-
- raw_spin_lock_irqsave(&rnp->lock, flags);
- smp_mb__after_unlock_lock();
- for (;;) {
- if (!sync_rcu_preempt_exp_done(rnp)) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
- break;
- }
- if (rnp->parent == NULL) {
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
- if (wake) {
- smp_mb(); /* EGP done before wake_up(). */
- wake_up(&rsp->expedited_wq);
- }
- break;
- }
- mask = rnp->grpmask;
- raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
- rnp = rnp->parent;
- raw_spin_lock(&rnp->lock); /* irqs already disabled */
- smp_mb__after_unlock_lock();
- rnp->expmask &= ~mask;
- }
-}
-
-/*
* Snapshot the tasks blocking the newly started preemptible-RCU expedited
* grace period for the specified rcu_node structure, phase 1. If there
* are such tasks, set the ->expmask bits up the rcu_node tree and also