rcu: Start RCU kthreads in TASK_INTERRUPTIBLE state

Upon creation, kthreads are in TASK_UNINTERRUPTIBLE state, which can
result in softlockup warnings.  Because some of RCU's kthreads can
legitimately be idle indefinitely, start them in TASK_INTERRUPTIBLE
state in order to avoid those warnings.

Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Paul E. McKenney 2011-05-25 13:42:06 -07:00 committed by Ingo Molnar
parent 08bca60a69
commit cc3ce5176d
2 changed files with 3 additions and 0 deletions

View File

@ -1648,6 +1648,7 @@ static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu)
if (IS_ERR(t)) if (IS_ERR(t))
return PTR_ERR(t); return PTR_ERR(t);
kthread_bind(t, cpu); kthread_bind(t, cpu);
set_task_state(t, TASK_INTERRUPTIBLE);
per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu; per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu;
WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL); WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL);
per_cpu(rcu_cpu_kthread_task, cpu) = t; per_cpu(rcu_cpu_kthread_task, cpu) = t;
@ -1755,6 +1756,7 @@ static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp,
if (IS_ERR(t)) if (IS_ERR(t))
return PTR_ERR(t); return PTR_ERR(t);
raw_spin_lock_irqsave(&rnp->lock, flags); raw_spin_lock_irqsave(&rnp->lock, flags);
set_task_state(t, TASK_INTERRUPTIBLE);
rnp->node_kthread_task = t; rnp->node_kthread_task = t;
raw_spin_unlock_irqrestore(&rnp->lock, flags); raw_spin_unlock_irqrestore(&rnp->lock, flags);
sp.sched_priority = 99; sp.sched_priority = 99;

View File

@ -1295,6 +1295,7 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
if (IS_ERR(t)) if (IS_ERR(t))
return PTR_ERR(t); return PTR_ERR(t);
raw_spin_lock_irqsave(&rnp->lock, flags); raw_spin_lock_irqsave(&rnp->lock, flags);
set_task_state(t, TASK_INTERRUPTIBLE);
rnp->boost_kthread_task = t; rnp->boost_kthread_task = t;
raw_spin_unlock_irqrestore(&rnp->lock, flags); raw_spin_unlock_irqrestore(&rnp->lock, flags);
sp.sched_priority = RCU_KTHREAD_PRIO; sp.sched_priority = RCU_KTHREAD_PRIO;