balloon_page_dequeue(9)

💖 balloon_page_dequeue(9) 💖

okay so bestie, welcome to the Kernel API Manual — bucket list item: understanding how a balloon driver gives a page back to the guest 🎈✨ This one's a kernel function, it lives in balloon_page_dequeue, and it's lowkey the "hand it back" half of the balloon page life cycle. Let's get into it 🫶

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🌸 NAME 🌸

balloon_page_dequeue — this is the function that removes a page from balloon's page list and returns its address, so the driver can go ahead and release that page. it's giving "you can have this back now" energy 💅

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✨ SYNOPSIS ✨

struct page * balloon_page_dequeue (struct balloon_dev_info *b_dev_info
);

yeah that's the whole signature, no cap. it hands you back a struct page * 🎀

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🦋 ARGUMENTS 🦋

• b_dev_info — the balloon device descriptor, i.e. the place we're grabbing a page from. this is where the page comes out of, bestie 🎈

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👑 DESCRIPTION 👑

so here's the deal 🔥 the driver must call this function to properly dequeue a previously enqueued page before it definitively releases that page back to the guest system. like, you can't just skip straight to the release. that's not the vibe. do the dequeue first, periodt 💅

Caller must perform its own accounting to make sure this function only gets called if some pages are actually enqueued. yes, that's on you, not on the function. keep your own tally, bestie 📋✨

and heads up 🙈 — this function may fail to dequeue some pages even if there are some enqueued pages, because the page list can be temporarily empty due to the compaction of isolated pages. so it's not a bug, it's just the list being briefly empty, iykyk 😭

TODO: remove the caller accounting requirements, and allow caller to wait until all pages can be dequeued. (future-us's problem, fr fr 🧚)

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⭐ RETURN ⭐

you get a struct page for the dequeued page, or NULL if no page was dequeued. that NULL is your "nope, nothing came out" signal 💀

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🌈 SEE ALSO 🌈

• Kernel file ./mm/balloon.c
• balloon_page_insert(9)
• balloon_page_finalize(9)
• balloon_page_list_enqueue(9)
• balloon_page_list_dequeue(9)
• balloon_page_alloc(9)
• balloon_page_enqueue(9)

go read the whole balloon squad, they're all iconic 👑

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okay that's the whole page!! 🎀 source is ./mm and it's dated October 2026 — so like, future-coded of it. mwah, go dequeue responsibly 💜🦋🌸