Function try_register_napi 

pub fn try_register_napi(
    ring: &IoUring,
    busy_poll_to_us: u32,
    prefer_busy_poll: bool,
) -> Result<bool>

Attempt to register NAPI busy-poll, treating ENOSYS as success.

Convenience wrapper for callers that want fire-and-forget semantics: returns Ok(true) if NAPI was registered, Ok(false) if the kernel doesn’t support it, and Err only on unexpected failures.