sched: Kill the broken and deadlockable cpuset_lock/cpuset_cpus_allowed_locked code

[safe/jmp/linux-2.6] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 52b7efd..c0b3ebc 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2296,11 +2296,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
                return dest_cpu;
 
        /* No more Mr. Nice Guy. */
-       if (dest_cpu >= nr_cpu_ids) {
-               rcu_read_lock();
-               cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
-               rcu_read_unlock();
-               dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
+       if (unlikely(dest_cpu >= nr_cpu_ids)) {
+               cpumask_copy(&p->cpus_allowed, cpu_possible_mask);
+               dest_cpu = cpumask_any(cpu_active_mask);
 
                /*
                 * Don't tell them about moving exiting tasks or
@@ -5866,7 +5864,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
-               cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
                migrate_live_tasks(cpu);
                rq = cpu_rq(cpu);
                kthread_stop(rq->migration_thread);
@@ -5879,7 +5876,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                rq->idle->sched_class = &idle_sched_class;
                migrate_dead_tasks(cpu);
                raw_spin_unlock_irq(&rq->lock);
-               cpuset_unlock();
                migrate_nr_uninterruptible(rq);
                BUG_ON(rq->nr_running != 0);
                calc_global_load_remove(rq);