Linux workqueue

struct workqueue_struct {
	struct list_head	pwqs;		 //所有pool workqueue 都添加到链表中
	struct list_head	list;		 //用于将工作队列添加到全局链表workqueues中

	struct mutex		mutex;		 
	int			work_color;	
	int			flush_color;	
	atomic_t		nr_pwqs_to_flush; 
	struct wq_flusher	*first_flusher;	
	struct list_head	flusher_queue;	
	struct list_head	flusher_overflow; 

	struct list_head	maydays;	 //rescue状态下的pool_workqueue添加到本链表中
	struct worker		*rescuer;	  //rescuer内核线程，用于处理内存紧张时创建工作线程失败的情况

	int			nr_drainers;	
	int			saved_max_active; 

	struct workqueue_attrs	*unbound_attrs;	
	struct pool_workqueue	*dfl_pwq;	

#ifdef CONFIG_SYSFS
	struct wq_device	*wq_dev;	
#endif
#ifdef CONFIG_LOCKDEP
	struct lockdep_map	lockdep_map;
#endif
	char			name[WQ_NAME_LEN]; 

	
	struct rcu_head		rcu;

	
	unsigned int		flags ____cacheline_aligned; 
	struct pool_workqueue __percpu *cpu_pwqs;   //Per-CPU都创建pool_workqueue
	struct pool_workqueue __rcu *numa_pwq_tbl[];   //Per-Node创建pool_workqueue
};

struct worker {
	
	union {
		struct list_head	entry;	 //用于添加到worker_pool的空闲链表中
		struct hlist_node	hentry;	 //用于添加到worker_pool的忙碌列表中
	};

	struct work_struct	*current_work;	 //当前正在处理的work
	work_func_t		current_func;	  //当前正在执行的work回调函数
	struct pool_workqueue	*current_pwq;  //指向当前work所属的pool_workqueue
	struct list_head	scheduled;	  //所有被调度执行的work都将添加到该链表中

	

	struct task_struct	*task;		  //指向内核线程
	struct worker_pool	*pool;		 //该worker所属的worker_pool
						
	struct list_head	node;		 //添加到worker_pool->workers链表中
						

	unsigned long		last_active;	
	unsigned int		flags;		
	int			id;		

	
	char			desc[WORKER_DESC_LEN];

	
	struct workqueue_struct	*rescue_wq;	

	
	work_func_t		last_func;
};

struct work_struct {
	atomic_long_t data;
	struct list_head entry;
	work_func_t func;
#ifdef CONFIG_LOCKDEP
	struct lockdep_map lockdep_map;
#endif
};

struct worker_pool {
	spinlock_t		lock;		
	int			cpu;		
	int			node;		
	int			id;		
	unsigned int		flags;		

	unsigned long		watchdog_ts;	

	struct list_head	worklist;	

	int			nr_workers;	
	int			nr_idle;	

	struct list_head	idle_list;	
	struct timer_list	idle_timer;	
	struct timer_list	mayday_timer;	

	
	DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER);
						

	struct worker		*manager;	
	struct list_head	workers;	
	struct completion	*detach_completion; 

	struct ida		worker_ida;	

	struct workqueue_attrs	*attrs;		
	struct hlist_node	hash_node;	
	int			refcnt;		

	
	atomic_t		nr_running ____cacheline_aligned_in_smp;

	
	struct rcu_head		rcu;
} ____cacheline_aligned_in_smp;

struct pool_workqueue {
	struct worker_pool	*pool;		
	struct workqueue_struct *wq;		
	int			work_color;	
	int			flush_color;	
	int			refcnt;		
	int			nr_in_flight[WORK_NR_COLORS];
						
	int			nr_active;	
	int			max_active;	
	struct list_head	delayed_works;	
	struct list_head	pwqs_node;	
	struct list_head	mayday_node;	

	
	struct work_struct	unbound_release_work;
	struct rcu_head		rcu;
} __aligned(1 << WORK_STRUCT_FLAG_BITS);