linux设备驱动 内核定时器

在 Linux 内核中，时间由一个名为 jiffies 的全局变量衡量，该变量标识系统启动以来经过的滴答数。在最低的级别上，计算滴答数的方式取决于正在运行的特定硬件平台；但是，滴答计数通常在一次中断期间仍然继续进行。

Linux 提供了一个简单的 API 来构造和管理计时器。它包含一些函数（和助手函数），用于创建、取消和管理计时器。



计时器通过 timer_list 结构定义，该结构包括实现一个计时器所需的所有数据（其中包括列表指针和在编译时配置的可选计时器统计数据）。从用户角度看，timer_list 包含一个过期时间，一个回调函数（当/如果计时器过期），以及一个用户提供的上下文。用户必须初始化计时器，可以采取几种方法，最简单的方法是调用 setup_timer，该函数初始化计时器并设置用户提供的回调函数和上下文。或者，用户可以设置计时器中的这些值（函数和数据）并简单地调用 init_timer。注意，init_timer 由 setup_timer 内部调用。

-linux device driver- kernel timers

In the Linux kernel, by the time a global variable named jiffies measure, the number of ticks since the start of the identification system variable passed. At the lowest level, to calculate the number of ticks depends on the specific hardware platform running　however, usually during the tick count interrupt still continues.

Linux provides a simple API to construct and manage timer. It contains a number of functions (and helper functions), it is used to create, manage and cancel timers.



Timer by timer_list structure definition, the structure includes a timer to achieve all of the data required (including list pointers and optional timer statistics at compile time configuration). From the user perspective, timer_list contains an expiration date, a callback function (when/if the timer expires), as well as the context of a user. The user must initialize the timer can be taken several ways, the easiest way is to call setup_timer, the function initial