task_work: documentation

static struct callback_head work_exited; /* all we need is ->next == NULL */

/**

 * task_work_add - ask the @task to execute @work->func()

 * @task: the task which should run the callback

 * @work: the callback to run

 * @notify: send the notification if true

 *

 * Queue @work for task_work_run() below and notify the @task if @notify.

 * Fails if the @task is exiting/exited and thus it can't process this @work.

 * Otherwise @work->func() will be called when the @task returns from kernel

 * mode or exits.

 *

 * This is like the signal handler which runs in kernel mode, but it doesn't

 * try to wake up the @task.

 *

 * RETURNS:

 * 0 if succeeds or -ESRCH.

 */

int

task_work_add(struct task_struct *task, struct callback_head *work, bool notify)

{

	return 0;

}

/**

 * task_work_cancel - cancel a pending work added by task_work_add()

 * @task: the task which should execute the work

 * @func: identifies the work to remove

 *

 * Find the last queued pending work with ->func == @func and remove

 * it from queue.

 *

 * RETURNS:

 * The found work or NULL if not found.

 */

struct callback_head *

task_work_cancel(struct task_struct *task, task_work_func_t func)

{

	return work;

}

/**

 * task_work_run - execute the works added by task_work_add()

 *

 * Flush the pending works. Should be used by the core kernel code.

 * Called before the task returns to the user-mode or stops, or when

 * it exits. In the latter case task_work_add() can no longer add the

 * new work after task_work_run() returns.

 */

void task_work_run(void)

{

	struct task_struct *task = current;