Task_struct

结构定义： Linux task_struct 结构中 涉及进程状态的属性有三个，其中进程对应的状态分为两类， 一类是运行中状态， 另一类是进程退出状态。 struct task_struct { ... /* -1 unrunnable, 0 runnable, >0 stopped: */ volatile long state; int exit_state; unsigned int flags; ... } 状态说明： TASK_RUNNING 等待运行状态 TASK_INTERRUPTIBLE 可中断睡眠状态 TASK_UNINTERRUPTIBLE 不可中断睡眠状态 TASK_STOPPED 停止状态（收到 SIGSTOP、SIGTTIN、SIGTSTP 、 SIG.TTOU信号后状态） TASK_TRACED 被调试状态 TASK_KILLABLE 新可中断睡眠状态 TASK_PARKED kthread_park使用的特殊状态 TASK_NEW 创建任务临时状态 TASK_DEAD 任务退出状态 TASK_WAKING 被唤醒状态 TASK_IDLE 任务空闲状态 /* * Task state bitmask. NOTE! These bits are also * encoded in fs/proc/array.c: get_task_state(). * * We have two separate sets of flags: task->state * is about runnability, while task->exit_state are * about the task exiting. Confusing, but this way * modifying one set can't modify the other one by * mistake. */ /* Used in tsk->state: */ #define TASK_RUNNING 0x0000 #define TASK_INTERRUPTIBLE 0x0001 #define TASK_UNINTERRUPTIBLE 0x0002 #define __TASK_STOPPED 0x0004 #define __TASK_TRACED 0x0008 /* Used in tsk->exit_state: */ #define EXIT_DEAD 0x0010 #define EXIT_ZOMBIE 0x0020 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) /* Used in tsk->state again: */ #define TASK_PARKED 0x0040 #define TASK_DEAD 0x0080 #define TASK_WAKEKILL 0x0100 #define TASK_WAKING 0x0200 #define TASK_NOLOAD 0x0400 #define TASK_NEW 0x0800 #define TASK_STATE_MAX 0x1000 /* Convenience macros for the sake of set_current_state: */ #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) /* Convenience macros for the sake of wake_up(): */ #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) /* get_task_state(): */ #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ TASK_PARKED) 相关代码： 下面通过内核代码，看下任务状态转换的一个大致过程。 ...