How is the Go scheduler (GMP model) structured?

The Go scheduler is based on the GMP model (Goroutine, Machine, Processor), which provides efficient concurrency management.

• G (Goroutine) — a lightweight thread of execution created by the program.
• M (Machine) — the system thread of the OS on which goroutines run.
• P (Processor) — a logical processor, a resource needed to run a goroutine on M.

Scheduler operation:

1. A goroutine (G) needs a P to execute.
2. P is linked to an M (OS thread), and G is run on this M.
3. If a goroutine blocks (e.g., on I/O), M is released, and P can switch to another goroutine.
4. The scheduler balances the load between M and G through P to maximize system resource utilization.

Thus, GMP allows efficient scaling of goroutine execution on multiprocessor systems, minimizing overhead for context switching and blocking.