Linked Lists and Work Queues

The use of standard kernel helper facilities simplifies your code, weeds out redundancies from the kernel, and helps long-term maintenance. And since the helpers are bug-free and optimized, you inherit those benefits for free.

Sreekrishnan Venkateswaran

Wednesday, March 15th, 2006

Share This:

Several useful helper interfaces exist in the kernel to make life easier for developers. One example is the doubly-linked list library. Many parts of the kernel need to maintain and manipulate linked lists of data structures. The kernel’s list… interface routines eliminate the need for chasing list pointers and debugging messy problems related to list maintenance. Another example of a useful helper facility is the seq_file interface, which simplifies the task of creating user space windows into your kernel code.

This month, let’s look at helper interfaces like lists, hlists, and work queues. The next couple of columns will look at helpers like seq files, completion functions, notifier blocks, kthreads, and more.

Be Lazy

There are equivalent ways to do what the many kernel helper facilities offer. For example, you can implement your own list manipulation routines instead of using the kernel’s list library, use kernel threads to defer work instead of submitting it to work queues, or add complexity to your process filesystem read() routines instead of using seq_files. However, the use of standard kernel helper interfaces simplifies your code, weeds out redundancies from the kernel, increases code readability, and simplifies long-term maintenance. And since the helpers are bug-free and optimized, you inherit those benefits with no additional effort.

Since the kernel is vast, you can always find parts that don’t take advantage of some of these mechanisms, so updating those code regions might be a good way to…

Please log in to view this content.

Not Yet a Member?

Hands-on Content
White Papers
Community Features
And more.

Already a Member?
Log in!

Forgotten your password?
Forgotten your username?