Work deferring mechanisms
Work deferring is a mechanism the Linux kernel offers. It allows you to defer work/a task until the system’s workload allows it to run smoothly or after a given time has lapsed. Depending on the type of work, the deferred task can run either in a process context or in an atomic context. It is common to using work deferring to complement the interrupt handler in order to compensate for some of its limitations, some of which are as follows:
- The interrupt handler must be as fast as possible, meaning that only a critical task should be performed in the handler so that the rest can be deferred later when the system is less busy.
- In the interrupt context, we cannot use blocking calls. The sleeping task should be scheduled in the process context.
The deferring work mechanism allows us to perform the minimum possible work in the interrupt handler (the so-called top-half, which runs in an interrupt context) and schedule an asynchronous action...
