Where can I find good open source code flow visualization software?

Question

I am working on an academic research regarding some very long functions in the Linux kernel (link, link).

For that research, I would like to use some code flow visualiza

Answer 1

Perhaps a tool like KCacheGrind would be of help. It generates call graphs based on actual calls and cannot pre-generate a call graph without actually running the program, which may not suit your needs, but then it again it may.