unmapped_area_topdown(9)

📦 version 7.3.1, in nixpkgs unstable

unmapped_area_topdown(9) 🦋

okay so this is from the Kernel API Manual and it's genuinely one of those function names that sounds like a spell, but bestie it's so good — it's literally the top-down twin of the whole "find me some memory" saga. sit down, hydrate, let's go 💖

NAME ✨

unmapped_area_topdown — find an area between the low_limit and the high_limit with the correct alignment and offset at the highest available address, all from @info. and like… heads up bestie: current->mm is used for the search 👀 (yes, that mm. the one you're thinking of.)

SYNOPSIS 🎀

unsigned long unmapped_area_topdown (struct vm_unmapped_area_info *info);

it takes one argument and it returns an unsigned long, periodt. 💅

ARGUMENTS 🌸

  • info — the unmapped area information, which is giving "everything you need to know, packaged cute". it includes the range [low_limit - high_limit), the alignment offset, and the mask. that's the whole vibe check: range, offset, mask. 🫶

RETURN ⭐

  • a memory address — iconic, we love a successful search 🔥
  • or -ENOMEM — the "bestie there is No Memory, I'm so sorry 😭" result
no cap, those are the only two outcomes listed. address or -ENOMEM, that's the whole story.

SEE ALSO 👑

Kernel file ./mm/vma.c — plus these absolute main characters:

okay that's the whole page, you ate it up fr fr 💜 and for the credits moment — this one lives in ./mm, dated October 2026, star of the show unmapped_area_topdown(9). go find that highest available address, queen. 🌈🍓

📦 where this page comes from