static inline int rt_policy(int policy)
{
- if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR))
+ if (policy == SCHED_FIFO || policy == SCHED_RR)
return 1;
return 0;
}
}
rcu_read_unlock();
}
+
+ if (wake_flags & WF_MIGRATED)
+ schedstat_inc(p, se.statistics.nr_wakeups_migrate);
+
#endif /* CONFIG_SMP */
schedstat_inc(rq, ttwu_count);
if (wake_flags & WF_SYNC)
schedstat_inc(p, se.statistics.nr_wakeups_sync);
- if (cpu != task_cpu(p))
- schedstat_inc(p, se.statistics.nr_wakeups_migrate);
-
#endif /* CONFIG_SCHEDSTATS */
}
if (p->sched_class->task_woken)
p->sched_class->task_woken(rq, p);
- if (unlikely(rq->idle_stamp)) {
+ if (rq->idle_stamp) {
u64 delta = rq->clock - rq->idle_stamp;
u64 max = 2*sysctl_sched_migration_cost;
if (!next)
smp_send_reschedule(cpu);
}
-#endif
+
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+static int ttwu_activate_remote(struct task_struct *p, int wake_flags)
+{
+ struct rq *rq;
+ int ret = 0;
+
+ rq = __task_rq_lock(p);
+ if (p->on_cpu) {
+ ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+ ttwu_do_wakeup(rq, p, wake_flags);
+ ret = 1;
+ }
+ __task_rq_unlock(rq);
+
+ return ret;
+
+}
+#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
+#endif /* CONFIG_SMP */
static void ttwu_queue(struct task_struct *p, int cpu)
{
#if defined(CONFIG_SMP)
if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) {
+ sched_clock_cpu(cpu); /* sync clocks x-cpu */
ttwu_queue_remote(p, cpu);
return;
}
while (p->on_cpu) {
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
/*
- * If called from interrupt context we could have landed in the
- * middle of schedule(), in this case we should take care not
- * to spin on ->on_cpu if p is current, since that would
- * deadlock.
+ * In case the architecture enables interrupts in
+ * context_switch(), we cannot busy wait, since that
+ * would lead to deadlocks when an interrupt hits and
+ * tries to wake up @prev. So bail and do a complete
+ * remote wakeup.
*/
- if (p == current) {
- ttwu_queue(p, cpu);
+ if (ttwu_activate_remote(p, wake_flags))
goto stat;
- }
-#endif
+#else
cpu_relax();
+#endif
}
/*
* Pairs with the smp_wmb() in finish_lock_switch().
p->sched_class->task_waking(p);
cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
- if (task_cpu(p) != cpu)
+ if (task_cpu(p) != cpu) {
+ wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu);
+ }
#endif /* CONFIG_SMP */
ttwu_queue(p, cpu);
idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
- cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
+ do_set_cpus_allowed(idle, cpumask_of(cpu));
/*
* We're having a chicken and egg problem, even though we are
* holding rq->lock, the cpu isn't yet set to this cpu so the
}
#ifdef CONFIG_SMP
+void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
+{
+ if (p->sched_class && p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, new_mask);
+ else {
+ cpumask_copy(&p->cpus_allowed, new_mask);
+ p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
+ }
+}
+
/*
* This is how migration works:
*
goto out;
}
- if (p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, new_mask);
- else {
- cpumask_copy(&p->cpus_allowed, new_mask);
- p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
- }
+ do_set_cpus_allowed(p, new_mask);
/* Can the task run on the task's current CPU? If so, we're done */
if (cpumask_test_cpu(task_cpu(p), new_mask))
return 0;
}
-static int
-cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *tsk, bool threadgroup)
-{
- int retval = cpu_cgroup_can_attach_task(cgrp, tsk);
- if (retval)
- return retval;
- if (threadgroup) {
- struct task_struct *c;
- rcu_read_lock();
- list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
- retval = cpu_cgroup_can_attach_task(cgrp, c);
- if (retval) {
- rcu_read_unlock();
- return retval;
- }
- }
- rcu_read_unlock();
- }
- return 0;
-}
-
static void
-cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cont, struct task_struct *tsk,
- bool threadgroup)
+cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
sched_move_task(tsk);
- if (threadgroup) {
- struct task_struct *c;
- rcu_read_lock();
- list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
- sched_move_task(c);
- }
- rcu_read_unlock();
- }
}
static void
.name = "cpu",
.create = cpu_cgroup_create,
.destroy = cpu_cgroup_destroy,
- .can_attach = cpu_cgroup_can_attach,
- .attach = cpu_cgroup_attach,
+ .can_attach_task = cpu_cgroup_can_attach_task,
+ .attach_task = cpu_cgroup_attach_task,
.exit = cpu_cgroup_exit,
.populate = cpu_cgroup_populate,
.subsys_id = cpu_cgroup_subsys_id,