本文共 2054 字，大约阅读时间需要 6 分钟。

kthread worker 起始就是kernel 帮用户开创建内核线程，简化复杂度。主要的函数有三个，其使用举例如下：创建一个worker：pool->worker = kthread_create_worker(0, "ib_fmr(%s)", device->name);给worker 分配工作	kthread_init_work(&pool->work, ib_fmr_cleanup_func);让worker 开始工作		kthread_queue_work(pool->worker, &pool->work);kthread worker 其实就是内核进程。具体我们看看kthread_create_worker的实现就明白了kthread_create_worker->__kthread_create_workerstatic __printf(3, 0) struct kthread_worker *__kthread_create_worker(int cpu, unsigned int flags,			const char namefmt[], va_list args){	struct kthread_worker *worker;	struct task_struct *task;	int node = -1;	worker = kzalloc(sizeof(*worker), GFP_KERNEL);	if (!worker)		return ERR_PTR(-ENOMEM);	kthread_init_worker(worker);	if (cpu >= 0)		node = cpu_to_node(cpu);#核心就是这行，创建一个内核线程	task = __kthread_create_on_node(kthread_worker_fn, worker,						node, namefmt, args);	if (IS_ERR(task))		goto fail_task;	if (cpu >= 0)		kthread_bind(task, cpu);	worker->flags = flags;	worker->task = task;#唤醒这个线程	wake_up_process(task);	return worker;fail_task:	kfree(worker);	return ERR_CAST(task);}给work赋值如下，可以看到就是给work->func赋值#define kthread_init_work(work, fn)					\	do {								\		memset((work), 0, sizeof(struct kthread_work));		\		INIT_LIST_HEAD(&(work)->node);				\		(work)->func = (fn);					\	} while (0)最后看一下如果让kthread worker来执行用户的回调函数bool kthread_queue_work(struct kthread_worker *worker,			struct kthread_work *work){	bool ret = false;	unsigned long flags;	spin_lock_irqsave(&worker->lock, flags);	if (!queuing_blocked(worker, work)) {#原来就是讲第二步的woker挂到worker->work_list 列表中		kthread_insert_work(worker, work, &worker->work_list);		ret = true;	}	spin_unlock_irqrestore(&worker->lock, flags);	return ret;}static void kthread_insert_work(struct kthread_worker *worker,				struct kthread_work *work,				struct list_head *pos){	kthread_insert_work_sanity_check(worker, work);	list_add_tail(&work->node, pos);	work->worker = worker;	if (!worker->current_work && likely(worker->task))#唤醒这个kthread 开始工作		wake_up_process(worker->task);}个人认为kthread worker主要减少用户创建内核线程的个数，通过上面的例子看一个kthread worker中可以执行多个回调函数

转载地址：http://upnmi.baihongyu.com/