The OP clearly states that he wants to know the earliest origin of the rule, and the only answers he gets are people giving their own opinions on how much swap space you should have.
Too bad because it's an interesting question that I would also like to know the answer to.
LowLevelKernel 6 minutes ago [-]
Curious, How much swap have you personally allocated on your personal setup?
Rendered at 00:22:57 GMT+0000 (Coordinated Universal Time) with Vercel.
Too bad because it's an interesting question that I would also like to know the answer to.