[dagmx]

You haven’t really expanded on why basing off the Linux kernel would have made more sense, especially at the time.

People have responded to you with timelines explaining why it couldn’t have happened but you seem to keep restating this claim without more substance or context to the time.

Imho Linux would have been the wrong choice and perhaps even the incorrect assumption. Mac is not really BSD based outside of the userland. The kernel was and is significantly different and would’ve hard forked from Linux if they did use it at the time.

Often when people say Linux they mean (the often memes) GNU/Linux , except GNU diverged significantly from the posix command line tools (in that sense macOS is truer) and the GPL3 license is anathema to Apple.

I don’t see any area where basing off Linux would have resulted in materially better results today.

[jart]

Well for starters, it would have better memory management. The XNU kernel's memory manager has poor time complexity. If I create a bunch of sparse memory maps using mmap() then XNU starts to croak once I have 10,000+ of them.

[dagmx]

Please re read the comment you’re responding to about how the kernel would have diverged significantly even if they did use the Linux kernel. Unless you think a three decade old kernel would have the same characteristics as today.

What benefit would it have had at the time? What guarantees would it have given at the time that would have persisted three decades later?