free_reserved_pages(9)

💖 NAME 💖

okay so this is the free_reserved_pages(9) page from the Kernel API Manual, and the name is literally doing the most: free_reserved_pages — free reserved pages. no cap, that's the whole assignment. ✨

✨ SYNOPSIS ✨

void free_reserved_pages (struct page *page , unsigned int order );

🎀 ARGUMENTS 🎀

• page — the first page to free. that's the starting point, bestie. 💅
• order — the page order to free. yes, the order matters, keep reading. 🫶

🦋 DESCRIPTION 🦋

It frees pages that were allocated through memblock during boot, letting the buddy manage them from now on. it's giving boot-time handoff realness. 🌸

bestie, the requirements are strict, okay? page must be naturally aligned to the order, and the order must not exceed MAX_PAGE_ORDER. All pages must be reserved. those are the facts, periodt. 💀

🌸 SEE ALSO 🌸

the kernel file ./mm/page_alloc.c has the whole squad, and you can lowkey go read all of these:

• __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)
• 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)

mwah 💅 this one's from ./mm, dated October 2026, and it's still out here being free_reserved_pages(9). iconic. 👑