diff options
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 35 |
1 files changed, 15 insertions, 20 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 8db0b597509..52db48e7f6e 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -67,9 +67,8 @@ struct workqueue_struct { #endif }; -/* All the per-cpu workqueues on the system, for hotplug cpu to add/remove - threads to each one as cpus come/go. */ -static DEFINE_MUTEX(workqueue_mutex); +/* Serializes the accesses to the list of workqueues. */ +static DEFINE_SPINLOCK(workqueue_lock); static LIST_HEAD(workqueues); static int singlethread_cpu __read_mostly; @@ -592,8 +591,6 @@ EXPORT_SYMBOL(schedule_delayed_work_on); * Returns zero on success. * Returns -ve errno on failure. * - * Appears to be racy against CPU hotplug. - * * schedule_on_each_cpu() is very slow. */ int schedule_on_each_cpu(work_func_t func) @@ -605,7 +602,7 @@ int schedule_on_each_cpu(work_func_t func) if (!works) return -ENOMEM; - preempt_disable(); /* CPU hotplug */ + get_online_cpus(); for_each_online_cpu(cpu) { struct work_struct *work = per_cpu_ptr(works, cpu); @@ -613,8 +610,8 @@ int schedule_on_each_cpu(work_func_t func) set_bit(WORK_STRUCT_PENDING, work_data_bits(work)); __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work); } - preempt_enable(); flush_workqueue(keventd_wq); + put_online_cpus(); free_percpu(works); return 0; } @@ -750,8 +747,10 @@ struct workqueue_struct *__create_workqueue_key(const char *name, err = create_workqueue_thread(cwq, singlethread_cpu); start_workqueue_thread(cwq, -1); } else { - mutex_lock(&workqueue_mutex); + get_online_cpus(); + spin_lock(&workqueue_lock); list_add(&wq->list, &workqueues); + spin_unlock(&workqueue_lock); for_each_possible_cpu(cpu) { cwq = init_cpu_workqueue(wq, cpu); @@ -760,7 +759,7 @@ struct workqueue_struct *__create_workqueue_key(const char *name, err = create_workqueue_thread(cwq, cpu); start_workqueue_thread(cwq, cpu); } - mutex_unlock(&workqueue_mutex); + put_online_cpus(); } if (err) { @@ -775,7 +774,7 @@ static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) { /* * Our caller is either destroy_workqueue() or CPU_DEAD, - * workqueue_mutex protects cwq->thread + * get_online_cpus() protects cwq->thread. */ if (cwq->thread == NULL) return; @@ -810,9 +809,11 @@ void destroy_workqueue(struct workqueue_struct *wq) struct cpu_workqueue_struct *cwq; int cpu; - mutex_lock(&workqueue_mutex); + get_online_cpus(); + spin_lock(&workqueue_lock); list_del(&wq->list); - mutex_unlock(&workqueue_mutex); + spin_unlock(&workqueue_lock); + put_online_cpus(); for_each_cpu_mask(cpu, *cpu_map) { cwq = per_cpu_ptr(wq->cpu_wq, cpu); @@ -835,13 +836,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, action &= ~CPU_TASKS_FROZEN; switch (action) { - case CPU_LOCK_ACQUIRE: - mutex_lock(&workqueue_mutex); - return NOTIFY_OK; - - case CPU_LOCK_RELEASE: - mutex_unlock(&workqueue_mutex); - return NOTIFY_OK; case CPU_UP_PREPARE: cpu_set(cpu, cpu_populated_map); @@ -854,7 +848,8 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, case CPU_UP_PREPARE: if (!create_workqueue_thread(cwq, cpu)) break; - printk(KERN_ERR "workqueue for %i failed\n", cpu); + printk(KERN_ERR "workqueue [%s] for %i failed\n", + wq->name, cpu); return NOTIFY_BAD; case CPU_ONLINE: |