1.图解进程管理-task_struct介绍

介绍了内核中task_struct结构体部分重要的成员变量的含义。

图片源文件路径

//https://elixir.bootlin.com/linux/v4.9.81/source/include/linux/sched.h#L1485
struct task_struct {
	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
	void *stack; //内核栈

	int on_rq;

	int prio, static_prio, normal_prio;
	unsigned int rt_priority;
	const struct sched_class *sched_class; //调度器类
	struct sched_entity se; //cfs进程调度实体
	struct sched_rt_entity rt; //rt进程调度实体
	struct task_group *sched_task_group;
	struct sched_dl_entity dl; //deadline进程调度实体
	unsigned int policy; //调度策略

	struct list_head tasks; //init_task的该链表记录了所有的进程
	struct mm_struct *mm, *active_mm;
	
	pid_t pid;
	pid_t tgid;
	/* PID/PID hash table linkage. */
	struct pid_link pids[PIDTYPE_MAX];
	struct list_head thread_group;
	struct list_head thread_node;
	/* namespaces */
	struct nsproxy *nsproxy;

	struct task_struct __rcu *real_parent; /* real parent process */
	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
	struct list_head children;	/* list of my children */
	struct list_head sibling;	/* linkage in my parent's children list */
	struct task_struct *group_leader;	/* threadgroup leader */

	char comm[TASK_COMM_LEN]; //相应的程序名

        struct fs_struct *fs; //用来表示进程与文件系统的联系，包括当前目录和根目录

        struct files_struct *files; //表示进程当前打开的文件

        struct signal_struct *signal; //进程的信号描述符
        struct sighand_struct *sighand; //进程的信号处理程序

        /* CPU-specific state of this task */
	struct thread_struct thread;
        int exit_code;
};