alloc_contig_range(9)

🧚 alloc_contig_range(9) 🧚

okay bestie, welcome to the Kernel API Manual entry for alloc_contig_range(9) — it's giving “I reserve a whole contiguous PFN range for you” energy, and honestly? iconic. 💅

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🌸 NAME 🌸

alloc_contig_range — tries to allocate given range of pages ✨

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🎀 SYNOPSIS 🎀

int alloc_contig_range (unsigned long start , unsigned long end ,
       acr_flags_t alloc_flags , gfp_t gfp_mask );

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🦋 ARGUMENTS 🦋

• start — start PFN to allocate
• end — one-past-the-last PFN to allocate
• alloc_flags — allocation information
• gfp_mask — GFP mask.

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💖 DESCRIPTION 💖

So this routine is a wrapper around alloc_contig_frozen_range, and the important vibe check is: it can't be used to allocate compound pages. Also, the refcount of each allocated page will be set to one. No cap. 🫶

All pages which PFN is in [start, end) are allocated for the caller, and should be freed with free_contig_range or by manually calling __free_page on each allocated page. Like, please clean up after yourself, bestie — the kernel is not your personal storage unit. 😭✨

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🔥 RETURN 🔥

zero on success or negative error code.

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👑 SEE ALSO 👑

Kernel file ./mm/page_alloc.c:

• __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)
• nr_free_buffer_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_frozen_pages(9)
• alloc_contig_pages(9)
• free_contig_frozen_range(9)
• free_contig_range(9)
• alloc_pages_nolock(9)

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mwah 💋 source/version line is ./mm, date is October 2026, and the manual name stays alloc_contig_range(9) — periodt. 🌈⭐