#endif
#include "sched.h"
-#include "../workqueue_sched.h"
+#include "../workqueue_internal.h"
#include "../smpboot.h"
#define CREATE_TRACE_POINTS
*/
static int select_fallback_rq(int cpu, struct task_struct *p)
{
- const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+ int nid = cpu_to_node(cpu);
+ const struct cpumask *nodemask = NULL;
enum { cpuset, possible, fail } state = cpuset;
int dest_cpu;
- /* Look for allowed, online CPU in same node. */
- for_each_cpu(dest_cpu, nodemask) {
- if (!cpu_online(dest_cpu))
- continue;
- if (!cpu_active(dest_cpu))
- continue;
- if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
- return dest_cpu;
+ /*
+ * If the node that the cpu is on has been offlined, cpu_to_node()
+ * will return -1. There is no cpu on the node, and we should
+ * select the cpu on the other node.
+ */
+ if (nid != -1) {
+ nodemask = cpumask_of_node(nid);
+
+ /* Look for allowed, online CPU in same node. */
+ for_each_cpu(dest_cpu, nodemask) {
+ if (!cpu_online(dest_cpu))
+ continue;
+ if (!cpu_active(dest_cpu))
+ continue;
+ if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
+ return dest_cpu;
+ }
}
for (;;) {
* It's the caller's job to ensure that the target task struct
* can't go away on us before we can do any checks.
*
- * Returns true if we indeed boosted the target task.
+ * Returns:
+ * true (>0) if we indeed boosted the target task.
+ * false (0) if we failed to boost the target.
+ * -ESRCH if there's no task to yield to.
*/
bool __sched yield_to(struct task_struct *p, bool preempt)
{
struct task_struct *curr = current;
struct rq *rq, *p_rq;
unsigned long flags;
- bool yielded = 0;
+ int yielded = 0;
local_irq_save(flags);
rq = this_rq();
again:
p_rq = task_rq(p);
+ /*
+ * If we're the only runnable task on the rq and target rq also
+ * has only one task, there's absolutely no point in yielding.
+ */
+ if (rq->nr_running == 1 && p_rq->nr_running == 1) {
+ yielded = -ESRCH;
+ goto out_irq;
+ }
+
double_rq_lock(rq, p_rq);
while (task_rq(p) != p_rq) {
double_rq_unlock(rq, p_rq);
}
if (!curr->sched_class->yield_to_task)
- goto out;
+ goto out_unlock;
if (curr->sched_class != p->sched_class)
- goto out;
+ goto out_unlock;
if (task_running(p_rq, p) || p->state)
- goto out;
+ goto out_unlock;
yielded = curr->sched_class->yield_to_task(rq, p, preempt);
if (yielded) {
resched_task(p_rq->curr);
}
-out:
+out_unlock:
double_rq_unlock(rq, p_rq);
+out_irq:
local_irq_restore(flags);
- if (yielded)
+ if (yielded > 0)
schedule();
return yielded;
*/
idle->sched_class = &idle_sched_class;
ftrace_graph_init_idle_task(idle, cpu);
+ vtime_init_idle(idle);
#if defined(CONFIG_SMP)
sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
#endif
struct task_group *sched_create_group(struct task_group *parent)
{
struct task_group *tg;
- unsigned long flags;
tg = kzalloc(sizeof(*tg), GFP_KERNEL);
if (!tg)
if (!alloc_rt_sched_group(tg, parent))
goto err;
+ return tg;
+
+err:
+ free_sched_group(tg);
+ return ERR_PTR(-ENOMEM);
+}
+
+void sched_online_group(struct task_group *tg, struct task_group *parent)
+{
+ unsigned long flags;
+
spin_lock_irqsave(&task_group_lock, flags);
list_add_rcu(&tg->list, &task_groups);
INIT_LIST_HEAD(&tg->children);
list_add_rcu(&tg->siblings, &parent->children);
spin_unlock_irqrestore(&task_group_lock, flags);
-
- return tg;
-
-err:
- free_sched_group(tg);
- return ERR_PTR(-ENOMEM);
}
/* rcu callback to free various structures associated with a task group */
/* Destroy runqueue etc associated with a task group */
void sched_destroy_group(struct task_group *tg)
+{
+ /* wait for possible concurrent references to cfs_rqs complete */
+ call_rcu(&tg->rcu, free_sched_group_rcu);
+}
+
+void sched_offline_group(struct task_group *tg)
{
unsigned long flags;
int i;
list_del_rcu(&tg->list);
list_del_rcu(&tg->siblings);
spin_unlock_irqrestore(&task_group_lock, flags);
-
- /* wait for possible concurrent references to cfs_rqs complete */
- call_rcu(&tg->rcu, free_sched_group_rcu);
}
/* change task's runqueue when it moves between groups.
}
#endif /* CONFIG_RT_GROUP_SCHED */
+int sched_rr_handler(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret;
+ static DEFINE_MUTEX(mutex);
+
+ mutex_lock(&mutex);
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+ /* make sure that internally we keep jiffies */
+ /* also, writing zero resets timeslice to default */
+ if (!ret && write) {
+ sched_rr_timeslice = sched_rr_timeslice <= 0 ?
+ RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice);
+ }
+ mutex_unlock(&mutex);
+ return ret;
+}
+
int sched_rt_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
return &tg->css;
}
+static int cpu_cgroup_css_online(struct cgroup *cgrp)
+{
+ struct task_group *tg = cgroup_tg(cgrp);
+ struct task_group *parent;
+
+ if (!cgrp->parent)
+ return 0;
+
+ parent = cgroup_tg(cgrp->parent);
+ sched_online_group(tg, parent);
+ return 0;
+}
+
static void cpu_cgroup_css_free(struct cgroup *cgrp)
{
struct task_group *tg = cgroup_tg(cgrp);
sched_destroy_group(tg);
}
+static void cpu_cgroup_css_offline(struct cgroup *cgrp)
+{
+ struct task_group *tg = cgroup_tg(cgrp);
+
+ sched_offline_group(tg);
+}
+
static int cpu_cgroup_can_attach(struct cgroup *cgrp,
struct cgroup_taskset *tset)
{
.name = "cpu",
.css_alloc = cpu_cgroup_css_alloc,
.css_free = cpu_cgroup_css_free,
+ .css_online = cpu_cgroup_css_online,
+ .css_offline = cpu_cgroup_css_offline,
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
.exit = cpu_cgroup_exit,
projects / deliverable / linux.git / blobdiff