vm_unmap_ram(9)

💅 vm_unmap_ram — bestie's guide to putting that address space back

okay so real talk, this is a page from the Kernel API Manual (section 9, the kernel-API girlies) and it's about vm_unmap_ram. that's it. that's the whole vibe. let's get into it 🎀

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✨ NAME ✨

vm_unmap_ram — unmap the linear kernel address space that got set up by vm_map_ram. yes bestie, it's the undo button 🫶

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🌸 SYNOPSIS 🌸

void vm_unmap_ram (const void *mem , unsigned int count );

that's the whole signature, no cap. it returns void — nothing comes back, it just does the thing 💅

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🦋 ARGUMENTS 🦋

• mem — the pointer that vm_map_ram handed you. like, the exact one. don't get cute with it.
• count — the count you passed to that vm_map_ram call. and listen: it cannot unmap partial 😭 so if you mapped 8 and you're trying to unmap 3, that's not a thing, the whole mapping goes or nothing goes. periodt.

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⭐ SEE ALSO ⭐

bestie this list is long but every single one is here, i'm not skipping a single crumb 🍓

• the kernel file ./mm/vmalloc.c (the source of truth, the main character)
• vunmap_range(9)
• vmap_pages_range(9)
• vm_area_map_pages(9)
• vm_area_unmap_pages(9)
• new_vmap_block(9)
• vm_unmap_aliases(9)
• vm_map_ram(9) — the one that started it all, the prequel 💖
• vm_area_add_early(9)
• vm_area_register_early(9)
• get_vm_area(9)
• find_vm_area(9)
• remove_vm_area(9)
• vfree_atomic(9)
• vfree(9)
• vunmap(9)
• vmap(9)
• vmap_pfn(9)
• __vmalloc_node_range(9)
• __vmalloc_node(9)
• vmalloc(9)
• vmalloc_huge_node(9)
• vzalloc(9)
• vmalloc_user(9)
• vmalloc_node(9)
• vzalloc_node(9)
• vrealloc_node_align(9)
• vmalloc_32(9)
• vmalloc_32_user(9)
• vread_iter(9)
• remap_vmalloc_range_partial(9)
• remap_vmalloc_range(9)
• pvm_find_va_enclose_addr(9)
• pvm_determine_end_from_reverse(9)
• pcpu_get_vm_areas(9)
• pcpu_free_vm_areas(9)

like i said. a whole squad. iykyk 💀

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⚠️ tiny but important vibe check: count has to match what you gave vm_map_ram, because partial unmapping is simply not on the menu. be normal about it.

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and that's the page, bestie!! written up all cute from the ./mm corner of the kernel tree, dated October 2026 — go unmap responsibly, mwah 💜✨