pcpu_map_pages(9)

💅 pcpu_map_pages — okay so this is a <rainbow>kernel API manual</rainbow> page, bestie

Hi hi! Welcome to the pcpu_map_pages(9) page — yes, the (9) means it's a kernel API section, iykyk. This is the one that maps pages into a pcpu_chunk, and honestly it's giving lowkey essential. Let's go 🫶

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✨ NAME ✨

pcpu_map_pages — map pages into a pcpu_chunk 🦋

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✨ SYNOPSIS ✨

int pcpu_map_pages (struct pcpu_chunk *chunk , struct page **pages , int
page_start , int page_end , gfp_t gfp );

That's the whole signature, fr fr — copy it exactly, don't be editing it 🙈

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✨ ARGUMENTS ✨

• chunk — the chunk of interest 💖 like, the one we're actually doing stuff to
• pages — the pages array, and it contains all the pages you wanna map
• page_start — page index of the first page to map 🌸
• page_end — page index of the last page to map + 1 ⭐ (yes, plus one — it's exclusive at the top end, don't forget the + 1 bestie)
• gfp — allocation flags, passed straight down to the underlying allocator 🎀

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✨ DESCRIPTION ✨

So for each cpu, this maps the pages in the range [page_start,page_end) into chunk. Slay. 🔥

Heads up: the caller is responsible for calling pcpu_post_map_flush after all the mappings are complete. Not before, not halfway through — after they're all done. That's on you, not on this function 💅

This function is also the one responsible for setting up whatever is necessary for reverse lookup (addr -> chunk). So it's out here doing the behind-the-scenes main character work 👑

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✨ SEE ALSO ✨

Go read these too, bestie — they're all canon 🌈

• Kernel file ./mm/percpu-vm.c
• pcpu_get_pages(9)
• pcpu_free_pages(9)
• pcpu_alloc_pages(9)
• pcpu_pre_unmap_flush(9)
• pcpu_unmap_pages(9)
• pcpu_post_unmap_tlb_flush(9)
• pcpu_post_map_flush(9)
• pcpu_populate_chunk(9)
• pcpu_depopulate_chunk(9)
• pcpu_should_reclaim_chunk(9)

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Anyways, that's the page! 🧚 For the record, the source directory is ./mm and this one's dated October 2026 — so yeah, it's timestamped from the future-ish, we love that for us 💀💜 Byeee, go map some pages responsibly! 🍓