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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-07-30 03:28:11 +0300
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-09-21 07:16:17 +0300
commitf4ecea309d3e17ba5e90082308125ad23bd5701b (patch)
treebf7623bc786bc0c9709a17aac6b459e7b1d21656 /kernel/rcu
parent19a5ecde086a6a5287978b12ae948fa691b197b7 (diff)
downloadlinux-f4ecea309d3e17ba5e90082308125ad23bd5701b.tar.xz
rcu: Use rsp->expedited_wq instead of sync_rcu_preempt_exp_wq
Now that there is an ->expedited_wq waitqueue in each rcu_state structure, there is no need for the sync_rcu_preempt_exp_wq global variable. This commit therefore substitutes ->expedited_wq for sync_rcu_preempt_exp_wq. It also initializes ->expedited_wq only once at boot instead of at the start of each expedited grace period. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c2
-rw-r--r--kernel/rcu/tree_plugin.h6
2 files changed, 3 insertions, 5 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 775d36cc0050..53d66ebb4811 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3556,7 +3556,6 @@ void synchronize_sched_expedited(void)
rcu_exp_gp_seq_start(rsp);
/* Stop each CPU that is online, non-idle, and not us. */
- init_waitqueue_head(&rsp->expedited_wq);
atomic_set(&rsp->expedited_need_qs, 1); /* Extra count avoids race. */
for_each_online_cpu(cpu) {
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
@@ -4179,6 +4178,7 @@ static void __init rcu_init_one(struct rcu_state *rsp,
}
init_waitqueue_head(&rsp->gp_wq);
+ init_waitqueue_head(&rsp->expedited_wq);
rnp = rsp->level[rcu_num_lvls - 1];
for_each_possible_cpu(i) {
while (i > rnp->grphi)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index b2bf3963a0ae..72df006de798 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -535,8 +535,6 @@ void synchronize_rcu(void)
}
EXPORT_SYMBOL_GPL(synchronize_rcu);
-static DECLARE_WAIT_QUEUE_HEAD(sync_rcu_preempt_exp_wq);
-
/*
* Return non-zero if there are any tasks in RCU read-side critical
* sections blocking the current preemptible-RCU expedited grace period.
@@ -590,7 +588,7 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
raw_spin_unlock_irqrestore(&rnp->lock, flags);
if (wake) {
smp_mb(); /* EGP done before wake_up(). */
- wake_up(&sync_rcu_preempt_exp_wq);
+ wake_up(&rsp->expedited_wq);
}
break;
}
@@ -729,7 +727,7 @@ void synchronize_rcu_expedited(void)
/* Wait for snapshotted ->blkd_tasks lists to drain. */
rnp = rcu_get_root(rsp);
- wait_event(sync_rcu_preempt_exp_wq,
+ wait_event(rsp->expedited_wq,
sync_rcu_preempt_exp_done(rnp));
/* Clean up and exit. */