* on line!
*/
WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0);
- phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1);
+ WARN_ON_ONCE(!list_empty(&t->rcu_node_entry));
+ phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1;
list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]);
- smp_mb(); /* Ensure later ctxt swtch seen after above. */
spin_unlock_irqrestore(&rnp->lock, flags);
}
* means that we continue to block the current grace period.
*/
rcu_preempt_qs(cpu);
+ local_irq_save(flags);
t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
+ local_irq_restore(flags);
}
/*
*/
for (;;) {
rnp = t->rcu_blocked_node;
- spin_lock(&rnp->lock);
+ spin_lock(&rnp->lock); /* irqs already disabled. */
if (rnp == t->rcu_blocked_node)
break;
- spin_unlock(&rnp->lock);
+ spin_unlock(&rnp->lock); /* irqs remain disabled. */
}
empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
list_del_init(&t->rcu_node_entry);
rcu_preempt_qs(cpu);
return;
}
- if (per_cpu(rcu_preempt_data, cpu).qs_pending) {
+ if (per_cpu(rcu_preempt_data, cpu).qs_pending)
t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
- }
}
/*
/*
* Because there is no preemptable RCU, there can be no readers blocked,
- * so there is no need to check for blocked tasks.
+ * so there is no need to check for blocked tasks. So check only for
+ * bogus qsmask values.
*/
static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
{
+ WARN_ON_ONCE(rnp->qsmask);
}
/*