Week 5 Session: What does it ask the kernel for?

Take the syscall inventory of a real program and decide which surface could actually host it

22 March 2027

This is the most open session of the semester, because almost anything can be traced. Use your assignment target if it is native.

Otherwise, pick something with a reputation:

• git — processes, filesystem, network, and a lot of them
• curl — a single clean network story
• ffmpeg — heavy compute with an awkward IO shape
• a package manager — the worst case, and the most instructive
• a language interpreter running a real script

Trace it. Count what it asks for, and sort the calls into: in preview1, in WASIX, in neither.

The number that matters is the third column, and the interesting part is usually not its size but its content. One fork is worse than four hundred reads. A single bind ends the conversation for an entire class of approach.

Two things to bring back:

• the smallest surface that would run your program unmodified
• the one call you would most like to delete from its requirements, and what it would cost the program to lose it

That second question is the week’s real content. Most of the engineering in this field is not implementing a syscall. It is arranging not to need it.