linux-stable/include/linux/kthread.h
Christoph Hellwig f624506f98 kthread: unexport kthread_blkcg
kthread_blkcg is only used by the built-in blk-cgroup code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220420042723.1010598-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-02 14:06:20 -06:00

226 lines
7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#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 mm_struct;
__printf(4, 5)
struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
void *data,
int node,
const char namefmt[], ...);
/**
* kthread_create - create a kthread on the current node
* @threadfn: the function to run in the thread
* @data: data pointer for @threadfn()
* @namefmt: printf-style format string for the thread name
* @arg: arguments for @namefmt.
*
* This macro will create a kthread on the current node, leaving it in
* the stopped state. This is just a helper for kthread_create_on_node();
* see the documentation there for more details.
*/
#define kthread_create(threadfn, data, namefmt, arg...) \
kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
void *data,
unsigned int cpu,
const char *namefmt);
void get_kthread_comm(char *buf, size_t buf_size, struct task_struct *tsk);
bool set_kthread_struct(struct task_struct *p);
void kthread_set_per_cpu(struct task_struct *k, int cpu);
bool kthread_is_per_cpu(struct task_struct *k);
/**
* 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; \
})
/**
* kthread_run_on_cpu - create and wake a cpu bound thread.
* @threadfn: the function to run until signal_pending(current).
* @data: data ptr for @threadfn.
* @cpu: The cpu on which the thread should be bound,
* @namefmt: printf-style name for the thread. Format is restricted
* to "name.*%u". Code fills in cpu number.
*
* Description: Convenient wrapper for kthread_create_on_cpu()
* followed by wake_up_process(). Returns the kthread or
* ERR_PTR(-ENOMEM).
*/
static inline struct task_struct *
kthread_run_on_cpu(int (*threadfn)(void *data), void *data,
unsigned int cpu, const char *namefmt)
{
struct task_struct *p;
p = kthread_create_on_cpu(threadfn, data, cpu, namefmt);
if (!IS_ERR(p))
wake_up_process(p);
return p;
}
void free_kthread_struct(struct task_struct *k);
void kthread_bind(struct task_struct *k, unsigned int cpu);
void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
int kthread_stop(struct task_struct *k);
bool kthread_should_stop(void);
bool kthread_should_park(void);
bool __kthread_should_park(struct task_struct *k);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_func(struct task_struct *k);
void *kthread_data(struct task_struct *k);
void *kthread_probe_data(struct task_struct *k);
int kthread_park(struct task_struct *k);
void kthread_unpark(struct task_struct *k);
void kthread_parkme(void);
void kthread_exit(long result) __noreturn;
void kthread_complete_and_exit(struct completion *, long) __noreturn;
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/kthread_flush_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);
void kthread_delayed_work_timer_fn(struct timer_list *t);
enum {
KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
};
struct kthread_worker {
unsigned int flags;
raw_spinlock_t lock;
struct list_head work_list;
struct list_head delayed_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;
/* Number of canceling calls that are running at the moment. */
int canceling;
};
struct kthread_delayed_work {
struct kthread_work work;
struct timer_list timer;
};
#define KTHREAD_WORK_INIT(work, fn) { \
.node = LIST_HEAD_INIT((work).node), \
.func = (fn), \
}
#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
.work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
TIMER_IRQSAFE), \
}
#define DEFINE_KTHREAD_WORK(work, fn) \
struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
struct kthread_delayed_work dwork = \
KTHREAD_DELAYED_WORK_INIT(dwork, fn)
extern void __kthread_init_worker(struct kthread_worker *worker,
const char *name, struct lock_class_key *key);
#define kthread_init_worker(worker) \
do { \
static struct lock_class_key __key; \
__kthread_init_worker((worker), "("#worker")->lock", &__key); \
} while (0)
#define kthread_init_work(work, fn) \
do { \
memset((work), 0, sizeof(struct kthread_work)); \
INIT_LIST_HEAD(&(work)->node); \
(work)->func = (fn); \
} while (0)
#define kthread_init_delayed_work(dwork, fn) \
do { \
kthread_init_work(&(dwork)->work, (fn)); \
timer_setup(&(dwork)->timer, \
kthread_delayed_work_timer_fn, \
TIMER_IRQSAFE); \
} while (0)
int kthread_worker_fn(void *worker_ptr);
__printf(2, 3)
struct kthread_worker *
kthread_create_worker(unsigned int flags, const char namefmt[], ...);
__printf(3, 4) struct kthread_worker *
kthread_create_worker_on_cpu(int cpu, unsigned int flags,
const char namefmt[], ...);
bool kthread_queue_work(struct kthread_worker *worker,
struct kthread_work *work);
bool kthread_queue_delayed_work(struct kthread_worker *worker,
struct kthread_delayed_work *dwork,
unsigned long delay);
bool kthread_mod_delayed_work(struct kthread_worker *worker,
struct kthread_delayed_work *dwork,
unsigned long delay);
void kthread_flush_work(struct kthread_work *work);
void kthread_flush_worker(struct kthread_worker *worker);
bool kthread_cancel_work_sync(struct kthread_work *work);
bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
void kthread_destroy_worker(struct kthread_worker *worker);
void kthread_use_mm(struct mm_struct *mm);
void kthread_unuse_mm(struct mm_struct *mm);
struct cgroup_subsys_state;
#ifdef CONFIG_BLK_CGROUP
void kthread_associate_blkcg(struct cgroup_subsys_state *css);
struct cgroup_subsys_state *kthread_blkcg(void);
#else
static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
#endif
#endif /* _LINUX_KTHREAD_H */