nr_free_buffer_pages(9)

✨ nr_free_buffer_pages 💖

okay bestie, so this one's a Linux kernel API manual page — it lives in section 9 of the kernel docs, which is the "kernel API" section iykyk. Think of it as the group chat for kernel devs. Anyways, let's get into it 🫶

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🌸 NAME 🌸

nr_free_buffer_pages — count number of pages beyond high watermark

(like, literally counting pages that are chillin' above the high watermark. that's the whole vibe check 💅)

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🦋 SYNOPSIS 🦋

unsigned long nr_free_buffer_pages (void );

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🎀 ARGUMENTS 🎀

• void — no arguments. absolutely none. zero. nada. it takes nothing, it needs nothing, it's giving low-maintenance icon energy ✨

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💜 DESCRIPTION 💜

so nr_free_buffer_pages counts the number of pages which are beyond the high watermark within ZONE_DMA and ZONE_NORMAL. that's it, that's the function. it's out here doing one job and doing it slay 🔥

(and yes, it's specifically those two zones — ZONE_DMA and ZONE_NORMAL. don't come for it about any other zones, it's not that girl 🙈)

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⭐ RETURN ⭐

number of pages beyond high watermark within ZONE_DMA and ZONE_NORMAL. like, the return value is literally just a count of those pages 🎀

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👑 SEE ALSO 👑

bestie, this list is LONG, so buckle up. it's all kernel file ./mm/page_alloc.c and friends:

• __get_pfnblock_flags_mask(9)
• get_pfnblock_bit(9)
• get_pfnblock_migratetype(9)
• __set_pfnblock_flags_mask(9)
• set_pfnblock_bit(9)
• clear_pfnblock_bit(9)
• set_pageblock_migratetype(9)
• __move_freepages_block_isolate(9)
• __putback_isolated_page(9)
• __free_pages(9)
• free_pages(9)
• alloc_pages_exact(9)
• alloc_pages_exact_nid(9)
• free_pages_exact(9)
• nr_free_zone_pages(9)
• find_next_best_node(9)
• free_reserved_pages(9)
• setup_per_zone_wmarks(9)
• __free_contig_range(9)
• alloc_contig_frozen_range(9)
• alloc_contig_range(9)
• alloc_contig_frozen_pages(9)
• alloc_contig_pages(9)
• free_contig_frozen_range(9)
• free_contig_range(9)
• alloc_pages_nolock(9)

they're all hanging out in ./mm together, it's a whole party 🌈

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okay and that's the whole page bestie!! 🧚 no cap, this was short but iconic 💅

source: ./mm · version drop: October 2026 · catch you on the flip side, love u, bye!! 💖🍓🦋