* [L] ->on_rq
* RELEASE (rq->lock)
*
- * If we observe the old CPU in task_rq_lock, the acquire of
+ * If we observe the old CPU in task_rq_lock(), the acquire of
* the old rq->lock will fully serialize against the stores.
*
- * If we observe the new CPU in task_rq_lock, the acquire will
- * pair with the WMB to ensure we must then also see migrating.
+ * If we observe the new CPU in task_rq_lock(), the address
+ * dependency headed by '[L] rq = task_rq()' and the acquire
+ * will pair with the WMB to ensure we then also see migrating.
*/
if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
rq_pin_lock(rq, rf);
if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY))
update_irq_load_avg(rq, irq_delta + steal);
#endif
+ update_rq_clock_pelt(rq, delta);
}
void update_rq_clock(struct rq *rq)
#endif
#endif
-/**
- * wake_q_add() - queue a wakeup for 'later' waking.
- * @head: the wake_q_head to add @task to
- * @task: the task to queue for 'later' wakeup
- *
- * Queue a task for later wakeup, most likely by the wake_up_q() call in the
- * same context, _HOWEVER_ this is not guaranteed, the wakeup can come
- * instantly.
- *
- * This function must be used as-if it were wake_up_process(); IOW the task
- * must be ready to be woken at this location.
- */
-void wake_q_add(struct wake_q_head *head, struct task_struct *task)
+static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task)
{
struct wake_q_node *node = &task->wake_q;
* state, even in the failed case, an explicit smp_mb() must be used.
*/
smp_mb__before_atomic();
- if (cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))
- return;
-
- get_task_struct(task);
+ if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL)))
+ return false;
/*
* The head is context local, there can be no concurrency.
*/
*head->lastp = node;
head->lastp = &node->next;
+ return true;
+}
+
+/**
+ * wake_q_add() - queue a wakeup for 'later' waking.
+ * @head: the wake_q_head to add @task to
+ * @task: the task to queue for 'later' wakeup
+ *
+ * Queue a task for later wakeup, most likely by the wake_up_q() call in the
+ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come
+ * instantly.
+ *
+ * This function must be used as-if it were wake_up_process(); IOW the task
+ * must be ready to be woken at this location.
+ */
+void wake_q_add(struct wake_q_head *head, struct task_struct *task)
+{
+ if (__wake_q_add(head, task))
+ get_task_struct(task);
+}
+
+/**
+ * wake_q_add_safe() - safely queue a wakeup for 'later' waking.
+ * @head: the wake_q_head to add @task to
+ * @task: the task to queue for 'later' wakeup
+ *
+ * Queue a task for later wakeup, most likely by the wake_up_q() call in the
+ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come
+ * instantly.
+ *
+ * This function must be used as-if it were wake_up_process(); IOW the task
+ * must be ready to be woken at this location.
+ *
+ * This function is essentially a task-safe equivalent to wake_q_add(). Callers
+ * that already hold reference to @task can call the 'safe' version and trust
+ * wake_q to do the right thing depending whether or not the @task is already
+ * queued for wakeup.
+ */
+void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task)
+{
+ if (!__wake_q_add(head, task))
+ put_task_struct(task);
}
void wake_up_q(struct wake_q_head *head)
{
lockdep_assert_held(&rq->lock);
- p->on_rq = TASK_ON_RQ_MIGRATING;
+ WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING);
dequeue_task(rq, p, DEQUEUE_NOCLOCK);
set_task_cpu(p, new_cpu);
rq_unlock(rq, rf);
INIT_HLIST_HEAD(&p->preempt_notifiers);
#endif
+#ifdef CONFIG_COMPACTION
+ p->capture_control = NULL;
+#endif
init_numa_balancing(clone_flags, p);
}
#endif
rq = __task_rq_lock(p, &rf);
update_rq_clock(rq);
- post_init_entity_util_avg(&p->se);
+ post_init_entity_util_avg(p);
activate_task(rq, p, ENQUEUE_NOCLOCK);
p->on_rq = TASK_ON_RQ_QUEUED;
}
#ifdef CONFIG_COMPAT_32BIT_TIME
-COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
- compat_pid_t, pid,
- struct old_timespec32 __user *, interval)
+SYSCALL_DEFINE2(sched_rr_get_interval_time32, pid_t, pid,
+ struct old_timespec32 __user *, interval)
{
struct timespec64 t;
int retval = sched_rr_get_interval(pid, &t);
/*
* There's no userspace yet to cause hotplug operations; hence all the
* CPU masks are stable and all blatant races in the below code cannot
- * happen. The hotplug lock is nevertheless taken to satisfy lockdep,
- * but there won't be any contention on it.
+ * happen.
*/
- cpus_read_lock();
mutex_lock(&sched_domains_mutex);
sched_init_domains(cpu_active_mask);
mutex_unlock(&sched_domains_mutex);
- cpus_read_unlock();
/* Move init over to a non-isolated CPU */
if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0)
add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}
EXPORT_SYMBOL(___might_sleep);
+
+void __cant_sleep(const char *file, int line, int preempt_offset)
+{
+ static unsigned long prev_jiffy;
+
+ if (irqs_disabled())
+ return;
+
+ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT))
+ return;
+
+ if (preempt_count() > preempt_offset)
+ return;
+
+ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
+ return;
+ prev_jiffy = jiffies;
+
+ printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line);
+ printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
+ in_atomic(), irqs_disabled(),
+ current->pid, current->comm);
+
+ debug_show_held_locks(current);
+ dump_stack();
+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
+}
+EXPORT_SYMBOL_GPL(__cant_sleep);
#endif
#ifdef CONFIG_MAGIC_SYSRQ
git.samba.org / sfrench / cifs-2.6.git / blobdiff