linux-2.6.33/__create_workqueue_key() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-2.6.33/__create_workqueue_key() へ行く。
  • 1 (2013-02-24 (日) 23:15:51)

---

参照元†

• linux-2.6.33/__create_workqueue()

説明†

• パス: linux-2.6.33/kernel/workqueue.c

• FIXME: これは何？
  • 説明

引数†

• const char *name
  • ワークキューの名前。
• int singlethread
• int freezeable
• int rt
• struct lock_class_key *key
  • linux-2.6.33/lock_class_key
• const char *lock_name

返り値†

• struct workqueue_struct *
  • ワークキューへのポインタ。失敗したときは NULL。

参考†

実装†

struct workqueue_struct *__create_workqueue_key(const char *name,
						int singlethread,
						int freezeable,
						int rt,
						struct lock_class_key *key,
						const char *lock_name)
{
	struct workqueue_struct *wq;
	struct cpu_workqueue_struct *cwq;
	int err = 0, cpu;

• • linux-2.6.33/workqueue_struct

• linux-2.6.33/cpu_workqueue_struct

	wq = kzalloc(sizeof(*wq), GFP_KERNEL);
	if (!wq)
		return NULL;

• • linux-2.6.33/GFP_KERNEL

• linux-2.6.33/kzalloc()

	wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct);
	if (!wq->cpu_wq) {
		kfree(wq);
		return NULL;
	}

• • linux-2.6.33/alloc_percpu()

	wq->name = name;
	lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
	wq->singlethread = singlethread;
	wq->freezeable = freezeable;
	wq->rt = rt;
	INIT_LIST_HEAD(&wq->list);

• • linux-2.6.33/lockdep_init_map()

• linux-2.6.33/INIT_LIST_HEAD()

	if (singlethread) {
		cwq = init_cpu_workqueue(wq, singlethread_cpu);
		err = create_workqueue_thread(cwq, singlethread_cpu);
		start_workqueue_thread(cwq, -1);

• singlethread_cpu は、static 変数、int 型
  • linux-2.6.33/init_cpu_workqueue()
  • linux-2.6.33/create_workqueue_thread()
  • linux-2.6.33/start_workqueue_thread()

	} else {
		cpu_maps_update_begin();

• • linux-2.6.33/cpu_maps_update_begin()

		/*
		 * We must place this wq on list even if the code below fails.
		 * cpu_down(cpu) can remove cpu from cpu_populated_map before
		 * destroy_workqueue() takes the lock, in that case we leak
		 * cwq[cpu]->thread.
		 */
		spin_lock(&workqueue_lock);
		list_add(&wq->list, &workqueues);
		spin_unlock(&workqueue_lock);

• • linux-2.6.33/spin_lock()

• linux-2.6.33/list_add()

• • linux-2.6.33/spin_unlock()

		/*
		 * We must initialize cwqs for each possible cpu even if we
		 * are going to call destroy_workqueue() finally. Otherwise
		 * cpu_up() can hit the uninitialized cwq once we drop the
		 * lock.
		 */
		for_each_possible_cpu(cpu) {

• • linux-2.6.33/for_each_possible_cpu()

			cwq = init_cpu_workqueue(wq, cpu);
			if (err || !cpu_online(cpu))
				continue;

• • linux-2.6.33/init_cpu_workqueue()

• linux-2.6.33/cpu_online()

			err = create_workqueue_thread(cwq, cpu);
			start_workqueue_thread(cwq, cpu);

• • linux-2.6.33/create_workqueue_thread()

• linux-2.6.33/start_workqueue_thead()

		}
		cpu_maps_update_done();

• • linux-2.6.33/cpu_maps_update_done()

	}

	if (err) {
		destroy_workqueue(wq);
		wq = NULL;
	}

• • linux-2.6.33/destroy_workqueue()

	return wq;
}
EXPORT_SYMBOL_GPL(__create_workqueue_key);

• GPL ライセンスのモジュールにのみシンボルを公開する。
  • linux-2.6.33/EXPORT_SYMBOL_GPL()

コメント†