[vlovich123]

Correct but you’d also still have that drag just from the kernel dirtying those caches in the first place.

But I was clarifying because the wording could be taken as data/instruction cache and there generally isn’t a full flush of that just to enter/leave kernel.

[slashdev]

Yes, that’s right. It seems to make up the bulk of the cost of a system call though, depending what it does, like read or write syscalls.