diff options
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6fedf3a98581..d8d76a65cfdd 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -24,7 +24,7 @@ DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) +#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL) /* * Debugging: various feature bits * @@ -396,6 +396,18 @@ static bool set_nr_if_polling(struct task_struct *p) #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) { struct wake_q_node *node = &task->wake_q; @@ -405,10 +417,11 @@ void wake_q_add(struct wake_q_head *head, struct task_struct *task) * its already queued (either by us or someone else) and will get the * wakeup due to that. * - * This cmpxchg() executes a full barrier, which pairs with the full - * barrier executed by the wakeup in wake_up_q(). + * In order to ensure that a pending wakeup will observe our pending + * state, even in the failed case, an explicit smp_mb() must be used. */ - if (cmpxchg(&node->next, NULL, WAKE_Q_TAIL)) + smp_mb__before_atomic(); + if (cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL)) return; get_task_struct(task); @@ -697,7 +710,7 @@ static void set_load_weight(struct task_struct *p, bool update_load) /* * SCHED_IDLE tasks get minimal weight: */ - if (idle_policy(p->policy)) { + if (task_has_idle_policy(p)) { load->weight = scale_load(WEIGHT_IDLEPRIO); load->inv_weight = WMULT_IDLEPRIO; p->se.runnable_weight = load->weight; @@ -2857,7 +2870,7 @@ unsigned long nr_running(void) * preemption, thus the result might have a time-of-check-to-time-of-use * race. The caller is responsible to use it correctly, for example: * - * - from a non-preemptable section (of course) + * - from a non-preemptible section (of course) * * - from a thread that is bound to a single CPU * @@ -3416,7 +3429,7 @@ static void __sched notrace __schedule(bool preempt) switch_count = &prev->nivcsw; if (!preempt && prev->state) { - if (unlikely(signal_pending_state(prev->state, prev))) { + if (signal_pending_state(prev->state, prev)) { prev->state = TASK_RUNNING; } else { deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK); @@ -4191,7 +4204,7 @@ recheck: * Treat SCHED_IDLE as nice 20. Only allow a switch to * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. */ - if (idle_policy(p->policy) && !idle_policy(policy)) { + if (task_has_idle_policy(p) && !idle_policy(policy)) { if (!can_nice(p, task_nice(p))) return -EPERM; } @@ -4450,7 +4463,7 @@ static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *a u32 size; int ret; - if (!access_ok(VERIFY_WRITE, uattr, SCHED_ATTR_SIZE_VER0)) + if (!access_ok(uattr, SCHED_ATTR_SIZE_VER0)) return -EFAULT; /* Zero the full structure, so that a short copy will be nice: */ @@ -4650,7 +4663,7 @@ static int sched_read_attr(struct sched_attr __user *uattr, { int ret; - if (!access_ok(VERIFY_WRITE, uattr, usize)) + if (!access_ok(uattr, usize)) return -EFAULT; /* @@ -5783,7 +5796,7 @@ int sched_cpu_deactivate(unsigned int cpu) * * Do sync before park smpboot threads to take care the rcu boost case. */ - synchronize_rcu_mult(call_rcu, call_rcu_sched); + synchronize_rcu(); #ifdef CONFIG_SCHED_SMT /* |