folio_put_swap(9)

📦 version 7.3.1, in nixpkgs unstable

💅 folio_put_swap — the kernel API manual, bestie edition 🎀

okay so real talk: we're in the Kernel API Manual today and the main character is folio_put_swap(9). pull up a chair, this one's short but she's important ✨

🌸 NAME 🌸

folio_put_swap — decreases the swap count of swap entries of a folio. that's it, that's the vibe. lowkey does exactly what it says on the tin 💖

✨ SYNOPSIS ✨

void folio_put_swap (struct folio *folio , struct page *page );

no return value, she just does the thing and dips 🫶

🦋 ARGUMENTS 🦋

  • folio — the folio with swap entries bounded. and like, pay attention here: it must be in the swap cache and locked. no exceptions, bestie, it's giving non-negotiable 💅
  • page — if it's not NULL, then you're only decreasing the swap count of this page. if it is NULL, well… you know what you signed up for 😌

🔥 DESCRIPTION 🔥

so here's the tea: this function will not free the swap slots, even if the swap count drops all the way to zero. why? because they're still pinned by the swap cache, periodt. 😭

if you do want them freed, the user may call folio_free_swap to free them. that's the move. iykyk 🧚

👑 CONTEXT 👑

the caller must ensure the folio is locked and in the swap cache. fr fr, do not skip this one, it's literally the whole assignment 💀

🌈 SEE ALSO 🌈

the kernel file ./mm/swapfile.c and her whole friend group:

⭐ reminder bestie: locked + in the swap cache, or this whole thing is a no-go 🍓

and that's the page!! mwah 💖 this lil icon lives under ./mm and was dated October 2026 — go off, ./mm, we stan a whole directory. 🎀🦋💜

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