It depends a lot on how often you’re trying to do it and the conditions you’re doing it under. I’ve worked on a couple of projects where I own an agent process

It depends a lot on how often you’re trying to do it and the conditions you’re doing it under. I’ve worked on a couple of projects where I own an agent process that runs on thousands of machines that are not mine (so I have no control of whether they are overloaded or in some pathological state), some of which are bumping up against memory and/or cpu and or IO limits, and a single blocking system call is many orders of magnitude more practical than the overhead of fork/exec and the dozens or hundreds of blocking system calls and memory allocations that entails. This is, of course, an extreme example. But there are definitely cases where it matters a lot.