[aerzen]

Spawning processes should not be on the hot path of any program.

[1718627440]

Why? That's a very useful processing primitive.

[lokar]

It’s a hack with many disadvantages. Sometimes a hack is the right answer, but the kernel should it add a primitive for it.

[MBCook]

Should bash link in every program the user might want? Load them up as dynamic libraries?

[lokar]

Bash as an interactive tool is very different. It is used to run an almost arbitrary number of things, and a pretty low rate.

Bash as a programming language is just a bad idea.

[m132]

Node, Python, PowerShell, and the rest do (almost) just that. launchd and systemd famously strived to remove as much shell from the start up process as possible because it was harming boot times and introducing unpredictability.

[sanderjd]

I don't know Node or PowerShell very well, but I'm not sure what you mean by this with respect to Python.

[m132]

CPython doesn't usually create subprocesses unless specifically asked to, it loads Python modules and native extensions into its process. The former is similar (you're still extending an existing process with new code, just interpreted), the latter is literally dlopen(), so loading dynamic libraries.

A lot of other Python implementations don't have the ability to spin up new processes at all too.

[sanderjd]

Aren't we discussing just such a primitive?

[lokar]

oh, sorry, typo

s/it/not/

[pizlonator]

It ends up on the hot path of programs that use process isolation aggressively

[lokar]

Sure, and there a primary thing you want is a whole new environment/context for the child (new environment, fds, memory, cgroups, namespaces, etc).