diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/lockdep.c | 2 | ||||
| -rw-r--r-- | kernel/sched.c | 33 | ||||
| -rw-r--r-- | kernel/time/clockevents.c | 5 | ||||
| -rw-r--r-- | kernel/timer.c | 15 |
4 files changed, 36 insertions, 19 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 63437d065ac8..298c9276dfdb 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3426,7 +3426,7 @@ int lock_is_held(struct lockdep_map *lock) int ret = 0; if (unlikely(current->lockdep_recursion)) - return ret; + return 1; /* avoid false negative lockdep_assert_held() */ raw_local_irq_save(flags); check_flags(flags); diff --git a/kernel/sched.c b/kernel/sched.c index cbb3a0eee58e..3f2e502d609b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -605,10 +605,10 @@ static inline int cpu_of(struct rq *rq) /* * Return the group to which this tasks belongs. * - * We use task_subsys_state_check() and extend the RCU verification - * with lockdep_is_held(&p->pi_lock) because cpu_cgroup_attach() - * holds that lock for each task it moves into the cgroup. Therefore - * by holding that lock, we pin the task to the current cgroup. + * We use task_subsys_state_check() and extend the RCU verification with + * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each + * task it moves into the cgroup. Therefore by holding either of those locks, + * we pin the task to the current cgroup. */ static inline struct task_group *task_group(struct task_struct *p) { @@ -616,7 +616,8 @@ static inline struct task_group *task_group(struct task_struct *p) struct cgroup_subsys_state *css; css = task_subsys_state_check(p, cpu_cgroup_subsys_id, - lockdep_is_held(&p->pi_lock)); + lockdep_is_held(&p->pi_lock) || + lockdep_is_held(&task_rq(p)->lock)); tg = container_of(css, struct task_group, css); return autogroup_task_group(p, tg); @@ -2200,6 +2201,16 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); #ifdef CONFIG_LOCKDEP + /* + * The caller should hold either p->pi_lock or rq->lock, when changing + * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. + * + * sched_move_task() holds both and thus holding either pins the cgroup, + * see set_task_rq(). + * + * Furthermore, all task_rq users should acquire both locks, see + * task_rq_lock(). + */ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || lockdep_is_held(&task_rq(p)->lock))); #endif @@ -2447,6 +2458,10 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) } rcu_read_unlock(); } + + if (wake_flags & WF_MIGRATED) + schedstat_inc(p, se.statistics.nr_wakeups_migrate); + #endif /* CONFIG_SMP */ schedstat_inc(rq, ttwu_count); @@ -2455,9 +2470,6 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) 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 */ } @@ -2600,6 +2612,7 @@ 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; } @@ -2674,8 +2687,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) 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); diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index c027d4f602f1..e4c699dfa4e8 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -182,7 +182,10 @@ void clockevents_register_device(struct clock_event_device *dev) unsigned long flags; BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); - BUG_ON(!dev->cpumask); + if (!dev->cpumask) { + WARN_ON(num_possible_cpus() > 1); + dev->cpumask = cpumask_of(smp_processor_id()); + } raw_spin_lock_irqsave(&clockevents_lock, flags); diff --git a/kernel/timer.c b/kernel/timer.c index fd6198692b57..8cff36119e4d 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -749,16 +749,15 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) unsigned long expires_limit, mask; int bit; - expires_limit = expires; - if (timer->slack >= 0) { expires_limit = expires + timer->slack; } else { - unsigned long now = jiffies; + long delta = expires - jiffies; + + if (delta < 256) + return expires; - /* No slack, if already expired else auto slack 0.4% */ - if (time_after(expires, now)) - expires_limit = expires + (expires - now)/256; + expires_limit = expires + delta / 256; } mask = expires ^ expires_limit; if (mask == 0) @@ -795,6 +794,8 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) */ int mod_timer(struct timer_list *timer, unsigned long expires) { + expires = apply_slack(timer, expires); + /* * This is a common optimization triggered by the * networking code - if the timer is re-modified @@ -803,8 +804,6 @@ int mod_timer(struct timer_list *timer, unsigned long expires) if (timer_pending(timer) && timer->expires == expires) return 1; - expires = apply_slack(timer, expires); - return __mod_timer(timer, expires, false, TIMER_NOT_PINNED); } EXPORT_SYMBOL(mod_timer); |