[LWN subscriber-only content] Welcome to LWN.net The following subscription-only content has been made available to you by an LWN subscriber. Thousands of subscribers depend on LWN for the best news from the Linux and free software communities. If you enjoy this article, please consider subscribing to LWN. Thank you for visiting LWN.net! Since the earliest days of Unix, two of the core process-oriented system calls have been fork(), which creates a child process as a copy of the parent, and e...