snapshot_additional_pages(9)

💖 snapshot_additional_pages(9) 💖

okay bestie, this page is straight out of the Kernel API Manual, and it’s all about one very specific estimate. Let’s get into it 🫶✨

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✨ NAME ✨

snapshot_additional_pages — Estimate the number of extra pages needed.

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🌸 SYNOPSIS 🌸

unsigned int snapshot_additional_pages (struct zone *zone );

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🎀 ARGUMENTS 🎀

• zone — Memory zone to carry out the computation for.

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🦋 DESCRIPTION 🦋

okay so snapshot_additional_pages() estimates the number of additional pages needed for setting up a hibernation image data structures for zone — yes, that’s the whole vibe, and it is an estimate, not a promise. Usually, the returned value is greater than the exact number, so it’s giving “estimate, not exact” energy 💅✨.

no cap, that’s literally the function’s whole job here. 🫶

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🔥 SEE ALSO 🔥

the kernel file ./kernel/power/snapshot.c, plus these iconic little references:

• get_image_page(9)
• free_image_page(9)
• alloc_rtree_node(9)
• free_mem_extents(9)
• create_mem_extents(9)
• memory_bm_next_pfn(9)
• mark_nosave_pages(9)
• create_basic_memory_bitmaps(9)
• free_basic_memory_bitmaps(9)
• count_free_highmem_pages(9)
• count_highmem_pages(9)
• count_data_pages(9)
• swsusp_free(9)
• preallocate_image_pages(9)
• free_unnecessary_pages(9)
• minimum_image_size(9)
• hibernate_preallocate_memory(9)
• pack_pfns(9)
• snapshot_read_next(9)
• unpack_orig_pfns(9)
• count_highmem_image_pages(9)
• prepare_highmem_image(9)
• copy_last_highmem_page(9)
• prepare_image(9)
• snapshot_write_next(9)
• restore_highmem(9)

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okay that’s the whole page, bestie 🎀 — it comes from ./kernel/power, dated October 2026, and honestly? iconic. 💅🌟