diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 19 | ||||
| -rw-r--r-- | kernel/cpuset.c | 14 | ||||
| -rw-r--r-- | kernel/time/timer_list.c | 41 | ||||
| -rw-r--r-- | kernel/workqueue.c | 9 |
4 files changed, 60 insertions, 23 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 781845a013ab..e91963302c0d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4480,6 +4480,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) struct dentry *d = cgrp->dentry; struct cgroup_event *event, *tmp; struct cgroup_subsys *ss; + struct cgroup *child; bool empty; lockdep_assert_held(&d->d_inode->i_mutex); @@ -4490,12 +4491,28 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) * @cgrp from being removed while __put_css_set() is in progress. */ read_lock(&css_set_lock); - empty = list_empty(&cgrp->cset_links) && list_empty(&cgrp->children); + empty = list_empty(&cgrp->cset_links); read_unlock(&css_set_lock); if (!empty) return -EBUSY; /* + * Make sure there's no live children. We can't test ->children + * emptiness as dead children linger on it while being destroyed; + * otherwise, "rmdir parent/child parent" may fail with -EBUSY. + */ + empty = true; + rcu_read_lock(); + list_for_each_entry_rcu(child, &cgrp->children, sibling) { + empty = cgroup_is_dead(child); + if (!empty) + break; + } + rcu_read_unlock(); + if (!empty) + return -EBUSY; + + /* * Block new css_tryget() by killing css refcnts. cgroup core * guarantees that, by the time ->css_offline() is invoked, no new * css reference will be given out via css_tryget(). We can't diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 010a0083c0ae..ea1966db34f2 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -475,13 +475,17 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) /* * Cpusets with tasks - existing or newly being attached - can't - * have empty cpus_allowed or mems_allowed. + * be changed to have empty cpus_allowed or mems_allowed. */ ret = -ENOSPC; - if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress) && - (cpumask_empty(trial->cpus_allowed) && - nodes_empty(trial->mems_allowed))) - goto out; + if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress)) { + if (!cpumask_empty(cur->cpus_allowed) && + cpumask_empty(trial->cpus_allowed)) + goto out; + if (!nodes_empty(cur->mems_allowed) && + nodes_empty(trial->mems_allowed)) + goto out; + } ret = 0; out: diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 3bdf28323012..61ed862cdd37 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -265,10 +265,9 @@ static inline void timer_list_header(struct seq_file *m, u64 now) static int timer_list_show(struct seq_file *m, void *v) { struct timer_list_iter *iter = v; - u64 now = ktime_to_ns(ktime_get()); if (iter->cpu == -1 && !iter->second_pass) - timer_list_header(m, now); + timer_list_header(m, iter->now); else if (!iter->second_pass) print_cpu(m, iter->cpu, iter->now); #ifdef CONFIG_GENERIC_CLOCKEVENTS @@ -298,33 +297,41 @@ void sysrq_timer_list_show(void) return; } -static void *timer_list_start(struct seq_file *file, loff_t *offset) +static void *move_iter(struct timer_list_iter *iter, loff_t offset) { - struct timer_list_iter *iter = file->private; - - if (!*offset) { - iter->cpu = -1; - iter->now = ktime_to_ns(ktime_get()); - } else if (iter->cpu >= nr_cpu_ids) { + for (; offset; offset--) { + iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); + if (iter->cpu >= nr_cpu_ids) { #ifdef CONFIG_GENERIC_CLOCKEVENTS - if (!iter->second_pass) { - iter->cpu = -1; - iter->second_pass = true; - } else - return NULL; + if (!iter->second_pass) { + iter->cpu = -1; + iter->second_pass = true; + } else + return NULL; #else - return NULL; + return NULL; #endif + } } return iter; } +static void *timer_list_start(struct seq_file *file, loff_t *offset) +{ + struct timer_list_iter *iter = file->private; + + if (!*offset) + iter->now = ktime_to_ns(ktime_get()); + iter->cpu = -1; + iter->second_pass = false; + return move_iter(iter, *offset); +} + static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) { struct timer_list_iter *iter = file->private; - iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); ++*offset; - return timer_list_start(file, offset); + return move_iter(iter, 1); } static void timer_list_stop(struct seq_file *seq, void *v) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 7f5d4be22034..e93f7b9067d8 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2201,6 +2201,15 @@ __acquires(&pool->lock) dump_stack(); } + /* + * The following prevents a kworker from hogging CPU on !PREEMPT + * kernels, where a requeueing work item waiting for something to + * happen could deadlock with stop_machine as such work item could + * indefinitely requeue itself while all other CPUs are trapped in + * stop_machine. + */ + cond_resched(); + spin_lock_irq(&pool->lock); /* clear cpu intensive status */ |