num_pages_contiguous(9)

💅 num_pages_contiguous(9) 💅

okay so welcome to the Kernel API Manual page for num_pages_contiguous, bestie. this one is literally about figuring out how many contiguous pages represent contiguous PFNs. it’s giving “how far does this run actually go” energy. ✨

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🌸 NAME 🌸

num_pages_contiguous — determine the number of contiguous pages that represent contiguous PFNs. yes, that is the whole assignment. 🎀

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✨ SYNOPSIS ✨

the signature is literally:

size_t num_pages_contiguous (struct page **pages , size_t nr_pages );

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🦋 ARGUMENTS 🦋

• pages — an array of page pointers. iconic array of struct page *, no cap.
• nr_pages — length of the array, and it has to be at least 1. not zero, okay? 😭

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💖 DESCRIPTION 💖

okay so num_pages_contiguous determines the number of contiguous pages that represent contiguous PFNs in pages, starting from the first page. main character energy: it starts at the beginning and checks the run. 👑

⚠️ important caveat, bestie: in some kernel configs, contiguous PFNs will not have contiguous struct pages. in these configurations, num_pages_contiguous will return a num smaller than ideal number. so the caller should continue to check for pfn contiguity after each call to num_pages_contiguous. do not assume one call tells you the whole story. 💀

it returns the number of contiguous pages. periodt. 💅

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🔥 SEE ALSO 🔥

• Kernel file ./include/linux/mm_inline.h
• folio_is_file_lru(9)
• __folio_clear_lru_flags(9)
• folio_lru_list(9)

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kisses from the Kernel API Manual corner of the group chat 💖 — source/version: ./include/linux, dated October 2026. num_pages_contiguous(9) out. 🎀🫶