Let's conclude this chapter by taking a very brief look at the evolution of our sed2 project to sed3. This mini-project is identical to sed2 except that it's simpler! The (en/de)crypt work is now carried out by our work task (function) via the kernel's workqueue functionality or bottom-half mechanism. We use a workqueue – the default kernel-global workqueue – to get the work done instead of manually creating and managing kthreads (as we did in sed2)!
The following screenshot shows us accessing the kernel log of a sample run; in the run, we had the user mode app encrypt, then decrypt, and then retrieve the message for viewing. We've highlighted the interesting bit here – the execution of our work task via the kernel-global workqueue's worker threads – in the two red rectangles:
