diff options
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 51eef4193e7..198e4df7d83 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1464,6 +1464,30 @@ static void invoke_rcu_node_kthread(struct rcu_node *rnp) } /* + * Set the specified CPU's kthread to run RT or not, as specified by + * the to_rt argument. The CPU-hotplug locks are held, so the task + * is not going away. + */ +static void rcu_cpu_kthread_setrt(int cpu, int to_rt) +{ + int policy; + struct sched_param sp; + struct task_struct *t; + + t = per_cpu(rcu_cpu_kthread_task, cpu); + if (t == NULL) + return; + if (to_rt) { + policy = SCHED_FIFO; + sp.sched_priority = RCU_KTHREAD_PRIO; + } else { + policy = SCHED_NORMAL; + sp.sched_priority = 0; + } + sched_setscheduler_nocheck(t, policy, &sp); +} + +/* * Timer handler to initiate the waking up of per-CPU kthreads that * have yielded the CPU due to excess numbers of RCU callbacks. * We wake up the per-rcu_node kthread, which in turn will wake up @@ -2166,9 +2190,11 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, case CPU_ONLINE: case CPU_DOWN_FAILED: rcu_node_kthread_setaffinity(rnp, -1); + rcu_cpu_kthread_setrt(cpu, 1); break; case CPU_DOWN_PREPARE: rcu_node_kthread_setaffinity(rnp, cpu); + rcu_cpu_kthread_setrt(cpu, 0); break; case CPU_DYING: case CPU_DYING_FROZEN: |