It only needs to save a few hundreds of seconds on one computer, or one second on a few hundreds of computers, or a tiny fraction of a second on the number of computers that actually run Linux to save trillions of cycles. A trillion cycles isn't very many at all. A hundred-word prompt on a frontier model running on GPUs in a datacentre burns much more power than a trillion cycles on a CPU, so for a large Linux kernel patch, trillions is the wrong number by many orders of magnitude. There are also a lot of computers spending a lot of time running Linux, so it kind of balances out. There's only one Linus Torvalds, and he's very busy, so it's likely that if he'd not used an LLM to get this work done, it simply wouldn't have happened, even if someone had been willing to fund a different human to do it.

Either way, the original point of the post was that LLM-generated code is always shitty (even when it's not immediately obvious to whoever's responsible for it that it's shitty) and so having any amount of it already makes things worse, even ignoring the huge environmental cost. With that context, it is the case that there's a huge difference between Timmy and Torvalds as Torvalds is famous for having very high standards, so if he's using it, he might be able to make something that isn't shitty.