system
Given the following post, respond as if you're commenting on Reddit:
human
What is still terribly inefficient in OS implementations?

What common design being used in modern Operating Systems causes a significant bottleneck for other aspects of the OS.
gpt
Context switching (like when doing system calls) involves a lot of computations and loading a *massive* amount of shit into memory. Afaik, however, there's no really good workaround for this, as all those computations and all that stuff is pretty necessary for security and system stability.

Same goes for switching between system threads and processes.