9  * task_work_add - ask the @task to execute @work->func()
11  * @work: the callback to run
14  * Queue @work for task_work_run() below and notify the @task if @notify
17  * work is run only when the task exits the kernel and returns to user mode,
19  * it can't process this @work. Otherwise @work->func() will be called when the
22  * If the targeted task is exiting, then an error is returned and the work item
32 int task_work_add(struct task_struct *task, struct callback_head *work,  in task_work_add()  argument
42 		work->next = head;  in task_work_add()
43 	} while (cmpxchg(&task->task_works, head, work) != head);  in task_work_add()
73  * task_work_cancel - cancel a pending work added by task_work_add()
74  * @task: the task which should execute the work
75  * @func: identifies the work to remove
77  * Find the last queued pending work with ->func == @func and remove
81  * The found work or NULL if not found.
87 	struct callback_head *work;  in task_work_cancel()  local
95 	 * new entry before this work, we will find it again. Or  in task_work_cancel()
99 	while ((work = READ_ONCE(*pprev))) {  in task_work_cancel()
100 		if (work->func != func)  in task_work_cancel()
101 			pprev = &work->next;  in task_work_cancel()
102 		else if (cmpxchg(pprev, work, work->next) == work)  in task_work_cancel()
107 	return work;  in task_work_cancel()
116  * new work after task_work_run() returns.
121 	struct callback_head *work, *head, *next;  in task_work_run()  local
125 		 * work->func() can do task_work_add(), do not set  in task_work_run()
130 			work = READ_ONCE(task->task_works);  in task_work_run()
131 			if (!work) {  in task_work_run()
137 		} while (cmpxchg(&task->task_works, work, head) != work);  in task_work_run()
139 		if (!work)  in task_work_run()
143 		 * the first entry == work, cmpxchg(task_works) must fail.  in task_work_run()
150 			next = work->next;  in task_work_run()
151 			work->func(work);  in task_work_run()
152 			work = next;  in task_work_run()
154 		} while (work);  in task_work_run()