diff options
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 58b1ebdc4387..c8340e929eb4 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -307,9 +307,11 @@ void rcu_read_unlock_special(struct task_struct *t) t->rcu_read_unlock_special.b.blocked = false; /* - * Remove this task from the list it blocked on. The - * task can migrate while we acquire the lock, but at - * most one time. So at most two passes through loop. + * Remove this task from the list it blocked on. The task + * now remains queued on the rcu_node corresponding to + * the CPU it first blocked on, so the first attempt to + * acquire the task's rcu_node's ->lock will succeed. + * Keep the loop and add a WARN_ON() out of sheer paranoia. */ for (;;) { rnp = t->rcu_blocked_node; @@ -317,6 +319,7 @@ void rcu_read_unlock_special(struct task_struct *t) smp_mb__after_unlock_lock(); if (rnp == t->rcu_blocked_node) break; + WARN_ON_ONCE(1); raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } empty_norm = !rcu_preempt_blocked_readers_cgp(rnp); |