What is the difference between Softirq and Tasklet?

Generally speaking, softirqs are re-entrant functions and must explicitly protect their data structures with spin locks. Tasklets differ from softirqs because a tasklet is always serialized with respect to itself; in other words, a tasklet cannot be executed by two CPUs at the same time.

What is a Tasklet?

Tasklets are a deferral scheme that you can schedule for a registered function to run later. The top half (the interrupt handler) performs a small amount of work, and then schedules the tasklet to execute later at the bottom half.

What is a Softirq?

SoftIrqs allow the critical part of servicing hardware interrupts to be as short as possible; instead of having to process the entire hw interrupt on the spot, the important data is read off the device into RAM or otherwise, and then a SoftIrq is started to finish the work.

What happens when a tasklet is disabled or enabled?

If it is disabled, it reinserts the task descriptor in the list pointed to by tasklet_vec [cpu] or tasklet_hi_vec [cpu]; then the function activates the TASKLET_SOFTIRQ or HI_SOFTIRQ softirq again. If the tasklet is enabled, clears the TASKLET_STATE_SCHED flag and executes the tasklet function.

How do I enable a tasklet in Java?

The tasklet can be declared and set at a disabled state, which means that the tasklet can be scheduled, but will not run until the tasklet is specifically enabled. You need to use tasklet_enable to enable. name – name of the structure to be created. func – This is the main function of the tasklet.

What is a tasklet?

Tasklets are the preferred way to implement deferrable functions in I/O drivers. As already explained, tasklets are built on top of two softirqs named HI_SOFTIRQ and TASKLET_SOFTIRQ. Several tasklets may be associated with the same softirq, each tasklet carrying its own function.

Can a tasklet be running in parallel?

Different tasklets can be running in parallel. But at the same time, a tasklet cannot be called concurrently with itself, as it runs on one CPU only. Tasklets are executed by the principle of non-preemptive scheduling, one by one, in turn. We can schedule them with two different priorities: normal and high.