diff options
| -rw-r--r-- | kernel/sched/core.c | 8 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 5 |
2 files changed, 11 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c5f020c601b2..ff4e3c066dc2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1063,8 +1063,12 @@ static int migration_cpu_stop(void *data) * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because * we're holding p->pi_lock. */ - if (task_rq(p) == rq && task_on_rq_queued(p)) - rq = __migrate_task(rq, p, arg->dest_cpu); + if (task_rq(p) == rq) { + if (task_on_rq_queued(p)) + rq = __migrate_task(rq, p, arg->dest_cpu); + else + p->wake_cpu = arg->dest_cpu; + } raw_spin_unlock(&rq->lock); raw_spin_unlock(&p->pi_lock); diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 4a1ca5f6da7e..082e71f17a58 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -126,6 +126,11 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) cpu_stop_init_done(&done, 1); if (!cpu_stop_queue_work(cpu, &work)) return -ENOENT; + /* + * In case @cpu == smp_proccessor_id() we can avoid a sleep+wakeup + * cycle by doing a preemption: + */ + cond_resched(); wait_for_completion(&done.completion); return done.ret; } |