root/include/linux/kthread.h

INCLUDED FROM

DEFINITIONS

1. __printf

#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>

__printf(4, 5)
struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
                                           void *data,
                                           int node,
                                           const char namefmt[], ...);

#define kthread_create(threadfn, data, namefmt, arg...) \
        kthread_create_on_node(threadfn, data, -1, namefmt, ##arg)


struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
                                          void *data,
                                          unsigned int cpu,
                                          const char *namefmt);

/**
 * 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);
bool kthread_should_stop(void);
bool kthread_should_park(void);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_data(struct task_struct *k);
void *probe_kthread_data(struct task_struct *k);
int kthread_park(struct task_struct *k);
void kthread_unpark(struct task_struct *k);
void kthread_parkme(void);

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().
 */
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     *current_work;
};

struct kthread_work {
        struct list_head        node;
        kthread_work_func_t     func;
        struct kthread_worker   *worker;
};

#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),                                                   \
        }

#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 needs its own lockdep class key when defined on
 * stack with lockdep enabled.  Use the following macros in such cases.
 */
#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)
#else
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
#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);                                    \
        } 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 */