The runqueue Data Structure    The runqueue lists link the process descriptors of all runnable processes--that is, of those in a TASK_RUNNING state--except the swapper process (idle proc

调度程序还提供了一种机制以支持交互进程    The scheduler provides one additional aide to interactive tasks: If a task is sufficiently interactive, when it exhausts its timeslice it will not be inserted into the expired a

时钟中断处理程序中会调用函数scheduler_tick():    函数scheduler_tick()更新当前进程的time_slice;并根据time_slice的使用情况(剩余还是耗尽)，来做进一步处理.scheduler_tick( ) Keeps the time_slice counter of current up-to-datevoid scheduler_tick(void){

    唤醒操作通过函数wake_up进行，它会唤醒指定的等待队列上的所有进程。它调用函数try_to_wake_up，该函数负责将进程设置为 TASK_RUNNING状态，调用activate_task将此进程放入可执行队列，如果被唤醒的进程优先级比当前正在运行的进程的优先级高，还有设 置need_resched标志。通常哪段代码促使等待条件达成，它就负责随后调用wake_up()函数。   

调用schedule()的时机Direct invocation(直接调用)    The scheduler is invoked directly when the current process must be blocked right away because the resource it needs is not available. In this case,

How Processes Are Organized------------------------------------        The runqueue lists group all processes in a TASK_RUNNING state. When it comes to grouping processes in other states, the various

TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE    Two states are associated with sleeping, TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE. They differ only in that tasks in the TASK_UNINTERRUPTIBL

Each process descriptor includes several fields related to scheduling:        thread_info     |--------------| +---|*task         | |   |--------------| |   |              | |   |--------------| |   |