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-rw-r--r--include/linux/sched.h3
-rw-r--r--kernel/rcutree_plugin.h8
2 files changed, 9 insertions, 2 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 496770a9648..76676a407e4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1254,6 +1254,9 @@ struct task_struct {
#ifdef CONFIG_PREEMPT_RCU
int rcu_read_lock_nesting;
char rcu_read_unlock_special;
+#if defined(CONFIG_RCU_BOOST) && defined(CONFIG_TREE_PREEMPT_RCU)
+ int rcu_boosted;
+#endif /* #if defined(CONFIG_RCU_BOOST) && defined(CONFIG_TREE_PREEMPT_RCU) */
struct list_head rcu_node_entry;
#endif /* #ifdef CONFIG_PREEMPT_RCU */
#ifdef CONFIG_TREE_PREEMPT_RCU
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 6abef3cfcbc..3a0ae035522 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -342,6 +342,11 @@ static void rcu_read_unlock_special(struct task_struct *t)
#ifdef CONFIG_RCU_BOOST
if (&t->rcu_node_entry == rnp->boost_tasks)
rnp->boost_tasks = np;
+ /* Snapshot and clear ->rcu_boosted with rcu_node lock held. */
+ if (t->rcu_boosted) {
+ special |= RCU_READ_UNLOCK_BOOSTED;
+ t->rcu_boosted = 0;
+ }
#endif /* #ifdef CONFIG_RCU_BOOST */
t->rcu_blocked_node = NULL;
@@ -358,7 +363,6 @@ static void rcu_read_unlock_special(struct task_struct *t)
#ifdef CONFIG_RCU_BOOST
/* Unboost if we were boosted. */
if (special & RCU_READ_UNLOCK_BOOSTED) {
- t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_BOOSTED;
rt_mutex_unlock(t->rcu_boost_mutex);
t->rcu_boost_mutex = NULL;
}
@@ -1176,7 +1180,7 @@ static int rcu_boost(struct rcu_node *rnp)
t = container_of(tb, struct task_struct, rcu_node_entry);
rt_mutex_init_proxy_locked(&mtx, t);
t->rcu_boost_mutex = &mtx;
- t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BOOSTED;
+ t->rcu_boosted = 1;
raw_spin_unlock_irqrestore(&rnp->lock, flags);
rt_mutex_lock(&mtx); /* Side effect: boosts task t's priority. */
rt_mutex_unlock(&mtx); /* Keep lockdep happy. */