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Diffstat (limited to 'include/linux/kthread.h')
| -rw-r--r-- | include/linux/kthread.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/include/linux/kthread.h b/include/linux/kthread.h new file mode 100644 index 00000000..1e923e5e --- /dev/null +++ b/include/linux/kthread.h @@ -0,0 +1,133 @@ +#ifndef _LINUX_KTHREAD_H +#define _LINUX_KTHREAD_H +/* Simple interface for creating and stopping kernel threads without mess. */ +#include <linux/err.h> +#include <linux/sched.h> + +struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), + void *data, + int node, + const char namefmt[], ...) + __attribute__((format(printf, 4, 5))); + +#define kthread_create(threadfn, data, namefmt, arg...) \ + kthread_create_on_node(threadfn, data, -1, namefmt, ##arg) + + +/** + * kthread_run - create and wake a thread. + * @threadfn: the function to run until signal_pending(current). + * @data: data ptr for @threadfn. + * @namefmt: printf-style name for the thread. + * + * Description: Convenient wrapper for kthread_create() followed by + * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). + */ +#define kthread_run(threadfn, data, namefmt, ...) \ +({ \ + struct task_struct *__k \ + = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ + if (!IS_ERR(__k)) \ + wake_up_process(__k); \ + __k; \ +}) + +void kthread_bind(struct task_struct *k, unsigned int cpu); +int kthread_stop(struct task_struct *k); +int kthread_should_stop(void); +void *kthread_data(struct task_struct *k); + +int kthreadd(void *unused); +extern struct task_struct *kthreadd_task; +extern int tsk_fork_get_node(struct task_struct *tsk); + +/* + * Simple work processor based on kthread. + * + * This provides easier way to make use of kthreads. A kthread_work + * can be queued and flushed using queue/flush_kthread_work() + * respectively. Queued kthread_works are processed by a kthread + * running kthread_worker_fn(). + * + * A kthread_work can't be freed while it is executing. + */ +struct kthread_work; +typedef void (*kthread_work_func_t)(struct kthread_work *work); + +struct kthread_worker { + spinlock_t lock; + struct list_head work_list; + struct task_struct *task; +}; + +struct kthread_work { + struct list_head node; + kthread_work_func_t func; + wait_queue_head_t done; + atomic_t flushing; + int queue_seq; + int done_seq; +}; + +#define KTHREAD_WORKER_INIT(worker) { \ + .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ + .work_list = LIST_HEAD_INIT((worker).work_list), \ + } + +#define KTHREAD_WORK_INIT(work, fn) { \ + .node = LIST_HEAD_INIT((work).node), \ + .func = (fn), \ + .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \ + .flushing = ATOMIC_INIT(0), \ + } + +#define DEFINE_KTHREAD_WORKER(worker) \ + struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) + +#define DEFINE_KTHREAD_WORK(work, fn) \ + struct kthread_work work = KTHREAD_WORK_INIT(work, fn) + +/* + * kthread_worker.lock and kthread_work.done need their own lockdep class + * keys if they are defined on stack with lockdep enabled. Use the + * following macros when defining them on stack. + */ +#ifdef CONFIG_LOCKDEP +# define KTHREAD_WORKER_INIT_ONSTACK(worker) \ + ({ init_kthread_worker(&worker); worker; }) +# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ + struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) +# define KTHREAD_WORK_INIT_ONSTACK(work, fn) \ + ({ init_kthread_work((&work), fn); work; }) +# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \ + struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn) +#else +# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) +# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn) +#endif + +extern void __init_kthread_worker(struct kthread_worker *worker, + const char *name, struct lock_class_key *key); + +#define init_kthread_worker(worker) \ + do { \ + static struct lock_class_key __key; \ + __init_kthread_worker((worker), "("#worker")->lock", &__key); \ + } while (0) + +#define init_kthread_work(work, fn) \ + do { \ + memset((work), 0, sizeof(struct kthread_work)); \ + INIT_LIST_HEAD(&(work)->node); \ + (work)->func = (fn); \ + init_waitqueue_head(&(work)->done); \ + } while (0) + +int kthread_worker_fn(void *worker_ptr); + +bool queue_kthread_work(struct kthread_worker *worker, + struct kthread_work *work); +void flush_kthread_work(struct kthread_work *work); +void flush_kthread_worker(struct kthread_worker *worker); + +#endif /* _LINUX_KTHREAD_H */ |