How does non-GC mode work? What are the pros & cons?

[igorgatis]

I went through the code but I could not quite understand how non-GC mode (MICROPY_ENABLE_GC = 0) works.

What are the main advantages of enabling/disabling GC?

[pfalcon]

"non-GC" mode works the way classical PHP did: it allocates memory, never frees. How useful is that, you can judge for yourself (people used old PHP and found it useful). For all practical purposes, ability to disable GC is debugging measure. (Or you can disable it, native uPy GC, and integrate another GC).