page_vma_map...walk_restart(9)

💅 page_vma_map...walk_restart(9) — the kernel API manual, bestie edition ✨

okay so this is one of those little kernel API pages (section 9 of the manual, iykyk) and honestly? she's short but she's important. let's get into it 🫶

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🌸 NAME 🌸

page_vma_mapped_walk_restart — literally just restart the page table walk. that's the whole vibe. 🔥

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✨ SYNOPSIS ✨

void page_vma_mapped_walk_restart (struct page_vma_mapped_walk *pvmw );

no return value, she just does the thing and leaves. main character energy honestly 💅

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🎀 ARGUMENTS 🎀

• pvmw — a pointer to struct page_vma_mapped_walk. that's it, that's the whole argument list. one girl, one pointer, one job 🦋

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💖 DESCRIPTION 💖

so here's the situation: sometimes stuff changes in the page table mid-walk — like when a PMD gets split (yes, mid-walk, messy 😭). when that happens, you gotta restart the page table walk, and that's exactly what this function is for.

what she does, in order, because we love a checklist:

• makes sure the PTL (that's the page table lock, bestie) held during the previous walk is released — no holding onto locks you don't need, we don't do that here 🙈
• resets the state so a brand new walk can start
• that new walk starts at the current address stored in pvmw->address — not from the top, from right where you're at. efficient. iconic. periodt ⭐

so like... it's giving "clean slate, but same address." 💜

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🌈 SEE ALSO 🌈

kernel file ./include/linux/rmap.h, and honestly the whole rmap fam is here:

• folio_dup_file_rmap_ptes(9)
• folio_dup_file_rmap_pmd(9)
• folio_try_dup_anon_rmap_ptes(9)
• folio_try_dup_anon_rmap_pmd(9)
• folio_try_share_anon_rmap_pte(9)
• folio_try_share_anon_rmap_pmd(9)

go read those too, they're all slay in their own way 👑

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ngl this one's a small page but it's load-bearing — if you're walking page tables and the table shifts under you, this is your girl. treat her right 🍓

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okay that's the whole page!! sign-off time: this one lives in ./include/linux, dated October 2026, and it's page_vma_map...walk_restart(9) — the truncated name is not a typo bestie, that's just how the header renders it 💀 ily, go split a PMD responsibly 🧚✨