The Linux kernel is interrupting the lower half of the

Let's start by explaining why the kernel divides interrupts into the upper and lower parts

Because the interrupt itself interrupts normal program execution, task scheduling cannot be performed in the interrupt, so the interrupt needs to be returned quickly, but some operations must be performed in the interrupt.

If the kernel needs to perform a hardware-related, time-sensitive, cannot be interrupted operation, then these operations should be placed in the top half, the other can postpone the operation should be placed in the lower part, so that the interruption must be completed in the operation, but also good scheduling.

Look at the kernel's support for the bottom half.

First say the following how to add your own soft interrupt program

First add your own soft break type, the lower the value the higher the priority

Using OPEN_SOFTIRQ to increase the corresponding interrupt processing function

Use RAISE_SOFTIRQ to interrupt your software effectively

The kernel will then be able to invoke the software interrupt in DO_SOFTIRQ.

And look at Tasklet.

Use the above 3 methods to declare your Tasklet

Of course to write your own execution function void func (unsigned long arg);

Add your own tasklet to the schedule with the above two functions

Of course there are corresponding functions to cancel their own tasklet, here does not introduce

Next look at the work queue Workqueue

The above method can be used to declare a work

Of course you have to write your own execution function

Use the above method to add work to the system Workquene

Of course, you can create your own work queue, and then join the work in your own working queue

The Linux kernel is interrupting the lower half of the