Isolating Patch Submissions by Type

The kernel development process is constantly evolving, as it has since Linus Torvalds figured out practices that were new to the relatively sluggish GNU project, making large-scale open source development actually work in practice. The first discoveries were the biggest – encouraging contributions from newcomers and putting out new releases rapidly. Nowadays most changes to the development process are relatively small and simple, like the following minor clarification that went down between Linus and a longtime developer, Eric Biggers.

Eric submitted a pull request for some patches to support SHA-384 and a few related APIs. These are cryptographic hashing algorithms designed by the US National Security Agency (NSA) and used all over the place. SHA-384 is just a shorter version of the more commonly known SHA-512. Eventually quantum computers will render these algorithms obsolete for security purposes, but for now they're still useful. In fact, a lot of Eric's patch simply migrated existing code from one place to another, improving the organization so multiple SHA algorithms would be easier to monitor. Along with the patches, Eric also included a big pile of test code, which intended to make sure the hashing implementations really did what they needed to. A cryptographic algorithm is only as good as its implementation.

But this was actually the thing Linus objected to. Linus replied:

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