Character device note-timer (timer)

 

Two timer elements:
1. Time
2. processing functions

How to use a timer?
1. Define/set a struct:
Static struct timer_list timer_task;

Init_timer (& timer_task );
Timer_task.function = gen_rtc_timer;
Timer_task.expires = maid + 100;

2. Tell the kernel about this struct: add_timer

3. Modify the timeout value:
Mod_timer

4. Remove the Timer:
Del_timer

Guess:
1. When the timer struct is told to the kernel, the kernel will put it into a linked list.
2. The system clock is interrupted every 10 ms, and jiffies ++
3. In the system clock interrupt processing function, the time value and

Jiffies
When it is equal, execute its processing function