clear_user_highpage(9)

💅 clear_user_highpage(9) — from the Kernel API Manual, bestie 🎀

okay so picture this: the kernel docs, but make it make sense. this one's from the Kernel API Manual, and it's about clearing a page so it can get mapped into user space. lowkey iconic behavior. ✨

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🌸 NAME 🌸

clear_user_highpage — literally clears a page so it's ready to be mapped to user space. that's the whole vibe. 💖

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🦋 SYNOPSIS 🦋

void clear_user_highpage (struct page *page , unsigned long vaddr );

the way it takes two args and returns nothing... main character energy fr fr. 🌈

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🎀 ARGUMENTS 🎀

• page — start page. yes bestie, the actual page. the starting one. 👑
• vaddr — start address of the user mapping. that's the address, in user space, where the mapping begins. 🫶

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✨ DESCRIPTION ✨

okay so here's the tea ☕ — with !CONFIG_HIGHMEM, this function (and the copy_user_highpage below) will be plain clear_user_page (and copy_user_page). that's it, that's the whole note. no cap, it's just a little "hey, in this config it's basically these other ones" heads up. 💀

highkey read that ! carefully — it means when CONFIG_HIGHMEM is not set. 🧚

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🍓 SEE ALSO 🍓

kernel file ./include/linux/highmem.h, plus the whole friend group:

• kmap(9)
• kunmap(9)
• kmap_to_page(9)
• kmap_flush_unused(9)
• kmap_local_page(9)
• kmap_local_folio(9)
• kmap_atomic(9)
• clear_user_page(9)
• clear_user_pages(9)
• clear_user_highpages(9)
• vma_alloc_zeroed_movable_folio(9)
• memcpy_from_folio(9)
• memcpy_to_folio(9)
• folio_zero_tail(9)
• folio_fill_tail(9)
• memcpy_from_file_folio(9)
• folio_zero_segments(9)
• folio_zero_segment(9)
• folio_zero_range(9)
• folio_release_kmap(9)

like, the whole highmem friend group showed OUT for this one. obsessed. 🔥

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and that's a wrap, bestie 🫶 this lil page lives in ./include/linux and it's dated October 2026, and yeah — <rainbow>clear_user_highpage(9)</rainbow> — slay, periodt, bye 💅