round_down(9)

📦 version 7.3.1, in nixpkgs unstable

💅 round_down(9) — the Kernel API Manual, bestie edition 🎀

okay so this is a page from the Kernel API Manual (yes, the round_down(9) one, we're literally here) and it's about the single most satisfying lil math helper ever. let's get into it ✨

💖 NAME 💖

round_down — round down to next specified power of 2 🫶

🌸 SYNOPSIS 🌸

round_down (x , y );

🦋 ARGUMENTS 🦋

  • x — the value to round, the main character we're rounding fr fr
  • y — the multiple to round down to, and listen 👏 it must be a power of 2 (no cap, that's the vibe check)

✨ DESCRIPTION ✨

Rounds x down to the next multiple of y — and again, y must be a power of 2, that is not a suggestion, it's giving requirement 💅.

and if you're sitting there like "but bestie, what if i need arbitrary rounding down??" — okay so for that you use rounddown instead, which is a whole different function, see below 👀. literally don't mix them up, i'm begging 🙈.

🔥 SEE ALSO 🔥

Kernel file ./include/linux/math.h — plus all these iconic siblings, go say hi:

they're all in there, it's a whole family, iykyk 🧚

quick vibe check recap so you don't forget: y = power of 2, always, or this whole thing is a mess 😭

and that's the page!! 🎀 sign-off from the ./include/linux corner of the world, dated October 2026, page round_down(9) — slay, ate, periodt, go round some numbers down down down 💜⭐

📦 where this page comes from