GIL switch interval impact on tail latency for CPU-bound threading

In standard Python 3.12 environments, the Global Interpreter Lock (GIL) manages thread execution via a fixed context switch interval. While I/O-bound tasks release the lock effectively, CPU-bound requests handled within the same process often encounter significant latency spikes under high concurrency.

The default switch interval of 5ms can lead to thread convoying, where multiple threads spend disproportionate time waiting for the lock rather than executing bytecode. This behavior is non-deterministic and relies heavily on the underlying OS thread scheduler, making it difficult to maintain consistent tail latency for CPU-intensive web applications without moving to a multi-processing architecture.

How does adjusting sys.setswitchinterval() specifically affect the P99 latency of concurrent CPU-intensive tasks? Is there a documented threshold where the overhead of frequent context switching outweighs the benefits of reduced lock‑acquisition wait time?