Post Syndicated from original https://lwn.net/Articles/925540/

The kernel’s software-interrupt (“softirq”) mechanism was added prior to
the 1.0 kernel release, but it implements a design seen in systems that were
already old when Linux was born. For much of that time, softirqs have been
an impediment to the kernel community’s scalability and response-time
goals, but they have proved resistant to removal. A recent discussion on a
proposed new heuristic to mitigate a softirq-related performance problem
may have reinvigorated interested in doing something about this subsystem
as a whole rather than just tweaking the parameters of how it operates.