[xroche]

> What kind of workloads spawn so many processes that saving microseconds becomes relevant?

With a huge process, you have a timeframe between the child is spawned and it executes exec*() where you typically "do stuff" (such as closing a lot of fd)

During this timeframe the parent process has its universe COW'ed, and each write will trigger a page fault.

The performance impact can be concerning in the _parent_ process.