When to use kernel threads vs workqueues in the linux kernel

Question

There are many ways to schedule work in the linux kernel: timers, tasklets, work queues, and kernel threads. What are the guidelines for when to use one vs another?

Answer 1

softirqs : deferred work runs in interrupt context
tasklets : deferred work runs in interrupt context
work queues : deferred work runs in process context

softirqs : cannot run simultaneously on different CPU's
tasklets : cannot run simultaneously on different CPU's
work queues : can run simultaneously on different CPU's

softirqs : cannot go to sleep
tasklets : cannot go to sleep
work queues : can go to sleep

softirqs : cannot be preempted/schedule
tasklets : cannot be preempted/schedule
work queues : maybe be preempted/schedule

softirqs : not easy to use
tasklets : easy to use
work queues : easy to use