> Some had facilities to define dedicated heap regions, but generally the GC had to walk the entire workstation heap across all "applications" in 1980s hardware

> Some had facilities to define dedicated heap regions, but generally the GC had to walk the entire workstation heap across all "applications" in 1980s hardware, which wasn't great. a stop-the-world global GC was generally tried to be avoided. mid 80s Symbolics Genera had regions for data types (areas), areas for manual memory management, a generational GC, incremental GC (the GC does some work while the programs are running) and an ephemeral GC efficiently tracking memory pages in RAM. For normal use it then looked like global stop-the-world GCs were only used in special situations like saving a GCed image or when running out of free memory. But one often preferred to add more virtual memory then, save the work and reboot. For that one could add paging space when Lisp crashed with an out-of-memory error and continue from there.