diff options
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f9a1346a5fa9..7880f4f64d0e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1656,7 +1656,8 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, if (cpumask_equal(p->cpus_ptr, new_mask)) goto out; - if (!cpumask_intersects(new_mask, cpu_valid_mask)) { + dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask); + if (dest_cpu >= nr_cpu_ids) { ret = -EINVAL; goto out; } @@ -1677,7 +1678,6 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, if (cpumask_test_cpu(task_cpu(p), new_mask)) goto out; - dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask); if (task_running(rq, p) || p->state == TASK_WAKING) { struct migration_arg arg = { p, dest_cpu }; /* Need help from migration thread: drop lock and wait. */ @@ -3254,7 +3254,7 @@ static struct rq *finish_task_switch(struct task_struct *prev) /* Task is done with its stack. */ put_task_stack(prev); - put_task_struct(prev); + put_task_struct_rcu_user(prev); } tick_nohz_task_switch(); @@ -3358,15 +3358,15 @@ context_switch(struct rq *rq, struct task_struct *prev, else prev->active_mm = NULL; } else { // to user + membarrier_switch_mm(rq, prev->active_mm, next->mm); /* * sys_membarrier() requires an smp_mb() between setting - * rq->curr and returning to userspace. + * rq->curr / membarrier_switch_mm() and returning to userspace. * * The below provides this either through switch_mm(), or in * case 'prev->active_mm == next->mm' through * finish_task_switch()'s mmdrop(). */ - switch_mm_irqs_off(prev->active_mm, next->mm, next); if (!prev->mm) { // from kernel @@ -4042,7 +4042,11 @@ static void __sched notrace __schedule(bool preempt) if (likely(prev != next)) { rq->nr_switches++; - rq->curr = next; + /* + * RCU users of rcu_dereference(rq->curr) may not see + * changes to task_struct made by pick_next_task(). + */ + RCU_INIT_POINTER(rq->curr, next); /* * The membarrier system call requires each architecture * to have a full memory barrier after updating @@ -4223,9 +4227,8 @@ static void __sched notrace preempt_schedule_common(void) #ifdef CONFIG_PREEMPTION /* - * this is the entry point to schedule() from in-kernel preemption - * off of preempt_enable. Kernel preemptions off return from interrupt - * occur there and call schedule directly. + * This is the entry point to schedule() from in-kernel preemption + * off of preempt_enable. */ asmlinkage __visible void __sched notrace preempt_schedule(void) { @@ -4296,7 +4299,7 @@ EXPORT_SYMBOL_GPL(preempt_schedule_notrace); #endif /* CONFIG_PREEMPTION */ /* - * this is the entry point to schedule() from kernel preemption + * This is the entry point to schedule() from kernel preemption * off of irq context. * Note, that this is called and return with irqs disabled. This will * protect us against recursive calling from irq. @@ -6069,7 +6072,8 @@ void init_idle(struct task_struct *idle, int cpu) __set_task_cpu(idle, cpu); rcu_read_unlock(); - rq->curr = rq->idle = idle; + rq->idle = idle; + rcu_assign_pointer(rq->curr, idle); idle->on_rq = TASK_ON_RQ_QUEUED; #ifdef CONFIG_SMP idle->on_cpu = 1; @@ -6430,8 +6434,6 @@ int sched_cpu_activate(unsigned int cpu) } rq_unlock_irqrestore(rq, &rf); - update_max_interval(); - return 0; } |