clear_flush_young_ptes(9)

💅 clear_flush_young_ptes(9) — Kernel API Manual, bestie edition 🎀

okay so like, welcome to the clear_flush_young_ptes(9) page from the Kernel API Manual ✨ — yes that whole title, we're keeping it, it's giving official. Sit down, grab a strawberry 🍓, and let's get into it.

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🌸 NAME 🌸

clear_flush_young_ptes — marks PTEs that map consecutive pages of the same folio as old, and flushes the TLB. literally that's the whole job. icon behavior tbh 👑

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✨ SYNOPSIS ✨

bool clear_flush_young_ptes (struct vm_area_struct *vma , unsigned long
addr , pte_t *ptep , unsigned int nr );

no cap, that's the signature, copy it exactly, don't be weird about the spacing 💖

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🦋 ARGUMENTS 🦋

• vma — the virtual memory area the pages are mapped into. like, the neighborhood the pages live in 🏡
• addr — the address the first page is mapped at. first one only, bestie, the rest follow along 🫶
• ptep — page table pointer for the first entry. your starting point 📍
• nr — number of entries to clear the access bit on. count 'em 🔢

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🧚 DESCRIPTION 🧚

So this one may be overridden by the architecture 😭 — meaning some arches go off and do their own thing with it. Otherwise? It's implemented as a simple loop over ptep_clear_flush_young. simple loop, simple life, we love a low-effort icon ✨

⚠️ heads up though: PTE bits in the PTE range besides the PFN can differ. for example, some PTEs might be write-protected. it's giving "same folio, different vibes" 💀 so don't assume they're identical just because they're neighbors.

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🔥 CONTEXT 🔥

the deets on when you can even call this:

• The caller holds the page table lock 🔒 no lock, no entry, periodt.
• The PTEs map consecutive pages that belong to the same folio 📚
• The PTEs are all in the same PMD 🎀

that's the vibe check, pass it before you call 💅

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🌈 SEE ALSO 🌈

Kernel file ./include/linux/pgtable.h — and honestly the whole friend group shows up here, so:

lazy_mmu_mode_enable(9), lazy_mmu_mode_disable(9), __task_lazy_mmu_mode_pause(9), lazy_mmu_mode_pause(9), __task_lazy_mmu_mode_resume(9), lazy_mmu_mode_resume(9), pte_batch_hint(9), set_ptes(9), clear_young_dirty_ptes(9), get_and_clear_full_ptes(9), get_and_clear_ptes(9), clear_full_ptes(9), clear_ptes(9), clear_nonpresent_ptes(9), ptep_try_set(9), flush_tlb_before_set(9), wrprotect_ptes(9), test_and_clear_young_ptes(9), modify_prot_start_ptes(9), modify_prot_commit_ptes(9), pfnmap_setup_cachemode(9), pfnmap_track(9), pfnmap_untrack(9), pfnmap_setup_cachemode_pfn(9)

like a whole crew, iykyk 😌

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okay and for the cute sign-off 🫶 this page lives in ./include/linux, it's dated October 2026, and it's filed under clear_flush_young_ptes(9) — mwah, go flush something, bestie 💜💅