pcpu_unmap_pages(9)

hii bestie 💖 this is pcpu_unmap_pages(9) from the Kernel API Manual, and it's giving “bye-bye pages” energy. lowkey important, so let’s get into it.

✨ NAME ✨

pcpu_unmap_pages — unmap pages out of a pcpu_chunk.

🌸 SYNOPSIS 🌸

void pcpu_unmap_pages (struct pcpu_chunk *chunk , struct page **pages ,
       int page_start , int page_end );

🎀 ARGUMENTS 🎀

• chunk — the chunk of interest 💖, aka the pcpu chunk we’re working with.
• pages — the pages array, which can be used to pass information to free 🫶.
• page_start — page index of the first page to unmap ✨.
• page_end — page index of the last page to unmap + 1 🔥. yes bestie, plus one — it’s that kind of range.

🔥 DESCRIPTION 🔥

okay so for each cpu, we unmap pages [page_start,page_end) out of chunk. periodt 💅.

The corresponding elements in pages were cleared by the caller, and they can be used to carry information to pcpu_free_pages, which will be called after all unmaps are finished. iykyk — the caller should call proper pre/post flush functions. no cap, that part is on you 🫶.

🦋 SEE ALSO 🦋

Kernel file ./mm/percpu-vm.c — the source file bestie ✨

• pcpu_get_pages(9)
• pcpu_free_pages(9)
• pcpu_alloc_pages(9)
• pcpu_pre_unmap_flush(9)
• pcpu_post_unmap_tlb_flush(9)
• pcpu_map_pages(9)
• pcpu_post_map_flush(9)
• pcpu_populate_chunk(9)
• pcpu_depopulate_chunk(9)
• pcpu_should_reclaim_chunk(9)

made with love from source/version ./mm, dated October 2026, for pcpu_unmap_pages(9) — mwah 💋💅✨